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iTunes Sales Not 'Collapsing' After All

john82 writes "Earlier this month we had a report from Forrester, based on a random sampling of 2,000 credit card accounts, that purported to show that iTunes sales were crashing. Now comes another survey from Reston, VA-based ComScore which indicates the exact opposite. ComScore's report which is based on actual iTunes sales shows a 84% increase during the first nine months of this year compared to the same period last year. Meanwhile the author of the Forrester report, Josh Bernoff, noted in his blog yesterday that they shouldn't be pummeled just because everyone took what he wrote and ran with it."

42 of 122 comments (clear)

  1. Own up to your reporting by BWJones · · Score: 5, Insightful

    Meanwhile the author of the Forrester report, Josh Bernoff, noted in his blog yesterday that they shouldn't be pummeled just because everyone took what he wrote and ran with it."

    Well, that is why people should be responsible for their reporting. In my business, when you report something, you stand by it. If you present data or a theory with the suspicion that it is incorrect, that is fraud in my line of work. Seriously though, did you *really* think that a sample size of just over 1000 purchases on credit cards obtained through a back channel source is a reliable sample size for the number of iTunes purchases? If I correctly recall, Apple announced back in February that they were selling about 3 million songs/day and if the current estimates of increases on the order of 84% are correct, your sample size is woefully under-representative. Thats just high school statistics by the way...

    I am not saying that you should lose your job over this one, but this should be a tacit reminder of how important good reporting is and if you are beyond your means or competence on a particular story or analysis, go find some help before you publish it, do some fact checking and be more careful with stories that can have a significant impact on companies and individuals.

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    1. Re:Own up to your reporting by RichPowers · · Score: 5, Insightful

      Indeed, he should stand by his work. But all of the websites and blogs weren't afraid to use Mr. Bernoff's report to drum up an Apple doom-and-gloom story for the sake of attracting readers.

    2. Re:Own up to your reporting by ceoyoyo · · Score: 4, Insightful

      A sample size of 1000 isn't necessarily inadequate... it depends on how much variance there is in the population and how big a change you're seeing. Those factors are normally summarized with a p-value, indicating how likely you are to be wrong.

      Naturally they didn't collect enough data to calculate a p-value... THAT was their mistake. Of course, nobody seems to do that, so really, it's par for the course.

    3. Re:Own up to your reporting by Gilmoure · · Score: 4, Funny

      Well, everyone knows that Apple is beleaguered and ready to die. Everyone knows that!

      --
      I drank what? -- Socrates
    4. Re:Own up to your reporting by kaleth · · Score: 3, Insightful
      Did you actually read the article? I'm not saying you should be banned from posting again over this one, but this should be a reminder of how important it is to have a clue before commenting. You clearly neglected to do any fact checking yourself. From the blog:

      "Our credit card transaction data shows a real drop between the January post-holiday peak and the rest of the year, but with the number of transactions we counted it's simply not possible to draw this conclusion . . . as we pointed out in the report."

      Seems to me like a pretty clear admission that the sample size is too small to be reliable. He took the data he had available, analyzed it, and presented the results while noting the deficiencies in the method. Doesn't sound much like fraud to me. That's just grade school reading by the way...

    5. Re:Own up to your reporting by lottameez · · Score: 3, Insightful

      I think everyone can also figure out that Apple probably didn't pay Forrester enough "research" fees.

      --
      Yeah? Well I think you're overrated too.
    6. Re:Own up to your reporting by wrook · · Score: 4, Informative

      Maybe this is obvious to people and maybe this isn't, but I thought I'd just clarify this in more standard lingo.

      The sample size you need to take for doing the study is dependent upon the probability that you expect the event to occur. So for example, out of 1000 random purchases, how many do you expect to be iTunes purchases? Most people buy a lot of things on their credit cards. So my guess is that only maybe 5 out of 1000 purchases would be iTunes purchases. The rest would be clothes, gas, groceries, restaurants meals, movies, gifts, etc, etc, etc.

      Let's say I'm right. If the expected value is 5 out of 1000, what are the odds that I might find 6 or 4 purchases in that sample? Well, depending on the distribution, it's not going to be that unusual. Remember, the *average* number you find will probably be about 5. If you actually look at 1000 random purchases, the actual amount you find will vary.

      So you might find 4 or even 3 with a pretty high probability (don't know off the top of my head what that probability is -- especially since I don't know the distribution of the data). So you have a pretty high probability of reporting something like 0.3% of purchases are iTunes purchases, when the real value is 0.5%. That's a *huge* error.

      But as others have said, the guys that do these studies know their stats. They don't put out crap reports by accident. They are intentionally misleading. Any reputable report that is based on statistical analysis will give you the error bars (i.e. + or - 5% 9 times out of 10). If this report had done this it would have said something like 65% reduction in sales +- 10% 1 time out of 10 (i.e. they aren't confident about their interval) or 65% reduction in sales +- 150% 9 times out of 10 (i.e. the error bars are totally crazy). And then it would be obvious the study was totally bogus.

      Note: All numbers I've used are fictional. I took stats 20 years ago and I *really* don't remember any of the actual numbers...

    7. Re:Own up to your reporting by HAKdragon · · Score: 4, Funny

      Apple Computer, on the verge of dying since 1976!

      --
      "Our opponent is an alien starship packed with atomic bombs. We have a protractor."
    8. Re:Own up to your reporting by ceoyoyo · · Score: 4, Insightful

      Problem is, you have to know that critical "how many purchases are iTunes purchases" value.

      The proper place to start is by taking last year's data (or last month's, or whatever) and measuring that value, then measuring it again today. Then you can ask the question whether iTunes sales have changed or not. Once you've shown there's a high probability that they've decreased (that might take ten samples, or it might take millions), THEN you can talk about how much they've decreased, and what sort of error bars go on that value.

      According to the original story they DID that, collecting data from 27 months... the difference between +80% and -60% is pretty huge... either they didn't do a simple t-test on their data, this was a VERY rare fluke or they decided to release their numbers anyway.

      It definitely sounds like they were paid for their result... I wonder if maybe they didn't expect someone with much better data to come around so quickly to slap them down.

      I also like the quote in the article about iTunes 1 billion dollars in sales not making up for the 2.5 billion dollar decrease in CD sales. Sounds about right to me. I doubt I'd purposely pay for more than a third of most albums.

    9. Re:Own up to your reporting by dcollins · · Score: 5, Informative

      "Seriously though, did you *really* think that a sample size of just over 1000 purchases on credit cards obtained through a back channel source is a reliable sample size for the number of iTunes purchases?... Thats just high school statistics by the way..."

      I'm a college professor of statistics. I don't think you can actually quote a high school statistics book which says that sample size is too small. In general, a sample size of 1,000 gives 95% confidence that your result is within +/-3% of the actual result. This is *regardless* of population size - that's how statisatics work, due to the Central Limit Theorem.

      http://en.wikipedia.org/wiki/Sample_size
      http://en.wikipedia.org/wiki/Central_limit_theorem

      Now, the first thing that pops into my head is why only credit-card purchases? And even more fundamentally, why would the same people need to buy music, after they just went on a music-buying spree? I would think the opposite. That was the thing that made me skeptical of the report yesterday in the first place.

      --
      We know where leadership by an anti-intellectual "strongman" who scapegoats minorities and likes boisterous rallies goes
    10. Re:Own up to your reporting by Evil+Dave+Letterman · · Score: 2, Informative

      1000 would be borderline statistically insignificant. If you read the post, he actually admitted that out of those, he only really used 181. Less than two hundred users out of 6 million!? And he has the nerve to blame everyone else for "misreporting" his findings? Saying you had any significant findings in a pool that ridiculously small, without any research into those customers' other possible methods for puchasing, is ridiculous.

    11. Re:Own up to your reporting by lendude · · Score: 5, Insightful
      That sentence you quote is having it both ways:

      "Our credit card transaction data shows a real drop (my emphasis) between the January post-holiday peak and the rest of the year, but with the number of transactions we counted it's simply not possible to draw this conclusion . . . as we pointed out in the report."

      There is no way that he can use the words "...real drop..." in the same sentence as "...it's simply not possible to draw this conclusion...". Whilst those who uncritically took the information from this 'research' and used it (doubtless with some sensationalistic agenda in mind) deserve scorn, that very sentence itself demonstrates the research to be nothing more than PR to flog the thing at $249.00 a pop. If you take out the words "real drop" and substitute "no meaningful change" then this report was clearly worth fuck-all: at least in terms of the author's now visible desire to have something sexy to sell!

      --
      "Get off the cross - we need the wood" - Tori Amos
    12. Re:Own up to your reporting by BWJones · · Score: 2, Informative

      You are focusing on the number when I should have put the emphasis on how the sample was selected. how about "did you *really* think that a sample size of just over 1000 purchases on credit cards obtained through a back channel source is a reliable sample size for the number of iTunes purchases?..."

      As one professor to another I am sure you also teach sampling error and experimental design, right? Additionally, it should be noted that the actual samples used for the analysis out of the total records pulled was less than 200. What does that do to power?

      --
      Visit Jonesblog and say hello.
    13. Re:Own up to your reporting by kfg · · Score: 2, Insightful

      Well, that is why people should be responsible for their reporting.

      Dude, it's a think tank "report." They deal in the amorphous and write it in weasel; 'cause it's a living paid for by the brainless. Put it under a rhetorical microscope and there's little there to be responsible for.

      The real title of this story should be "Think Tanker admits he shits for money."

      KFG

    14. Re:Own up to your reporting by MrMickS · · Score: 4, Insightful
      Most people didn't refer to his report. Rather they referred to an article on The Register instead. The author of The Register article has a history of anti-iTunes store articles and an anti-DRM agenda. He took what he wanted from the report to back up his viewpoint. The real problem is the way that this was swallowed by the rest without checking the source themselves.

      Sadly this seems to be the deal in journalism at the moment. Everything is sacrificed in order to be first to publish or, if not first then, not too far behind. Accuracy appears to be sacrificed in the race to publish.

      --
      You may think me a tired, old, cynic. I'd have to disagree about the tired bit.
    15. Re:Own up to your reporting by madth3 · · Score: 2
      Sadly this seems to be the deal in journalism at the moment. Everything is sacrificed in order to be first to publish or, if not first then, not too far behind. Accuracy appears to be sacrificed in the race to publish.
      Transmetropolitan, anyone?
    16. Re:Own up to your reporting by ceoyoyo · · Score: 2, Insightful

      You're not correct. To determine whether two populations are different (which is what these guys are trying to do), you need to know both the variance in the population and the two means. Since you have to know the entire population to actually measure either, you estimate them, using a sample of that population.

      As the number of samples increases, your estimates improve. However, you can't just say "you need a 10% sample" to be accurate. It doesn't work that way. The size of the sample you need depends on how much the populations vary and how far apart the means are.

      Look at what you've said about the p-value. "[The p-value] is a measure of how likely your results are do [sic] to chance." The p-value is a measure of how likely your result is due simply to chance, ie, it is incorrect.

      The situation is a bit more complicated for determining confidence intervals (which should have bee these guys' SECOND step). It still doesn't depend on the magnitude of the population though. here is a page describing the process if you're interested. Note that it doesn't depend on the population size.

      Also, this talks about some of the common rules of thumb that are used. Note that they don't depend on the magnitude of the population either.

      I hate to tell you, but likely in any important application you can think of nobody uses sample sizes anywhere near 10%. I work in medical studies and it's considered unethical to enroll more subjects in a study than are required. So you do a little pilot study to estimate the characteristics of the populations, then run the numbers to see how big N needs to be to achieve a significant result, then you propose THAT number to the ethics committee as a sample size.

    17. Re:Own up to your reporting by drsquare · · Score: 2, Interesting

      So if you look at a thousand credit card transactions in 2005, and there are two itunes songs bought, then if you look at a thousand credit card transactions in 2006, and only one itunes song is bought, then you are 95% sure that itunes sales have halved?

      And you're a professor for which university?

  2. Re:Own up to your reporting "I stand..." by Elsan · · Score: 5, Funny

    I stand by this man as long as he isn't proven wrong.

  3. ComScore by TheRealMindChild · · Score: 4, Informative

    ComScore. With a reputation like theirs, it must be true!

    --

    "When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
    1. Re:ComScore by Goaway · · Score: 2, Funny

      Well, they if anyone would know, wouldn't they?

  4. liars, crooks, and analysts by joe_bruin · · Score: 4, Insightful

    Technology sector analysts, the likes of Forrester and Gartner, are essentially paid mouthpieces for their biggest clients. Whether pumping your own products or badmounthing the competition, you can count on these guys to earn their money with totally bogus conclusions.

    Find a big analyst company that will admit that Itanium is a colossal disaster, that businesses don't want and don't need Vista, that HP's supply line trouble and incompetent management are sinking the company (particularly during the Carly years), that Oracle is terribly insecure. You won't, because they all have contracts with Intel, Microsoft, HP, Oracle, etc. But they won't hesitate to beat up on Sun (how many times have they called for McNealy's resignation), AMD, Apple, and predict their doom*, and others that don't spend the kind of money on various analysis contracts.

    So sure, iTunes sales are collapsing (according to Forrester), but nobody will call Zune a turd. It's all in a day's work.

    *disclaimer: I might be considered a fanboy of one of these companies, and it's not Apple

    1. Re:liars, crooks, and analysts by badonkey · · Score: 3, Funny

      I might be considered a fanboy of one of these companies, and it's not Apple

      You're a fanboy of Forrester and Gartner, too?!?

  5. Re:*Yawn* by SoLoman33333 · · Score: 2, Funny

    Ah yes, truthiness. How I've missed thee...

  6. Gift Cards by Foerstner · · Score: 4, Insightful

    For that matter, the Forrester data was based on credit card payments on the iTunes Store.

    It totally ignored the little lime-green $15 gift cards that litter the checkout stands of every Target, Best Buy, CVS Pharmacy, and Kroger in the US. Each one of those is 15 songs, and fifteen purchases that don't register as credit card transactions.

    --
    The US free market: two halves of a government-granted duopoly are free to set the market price.
  7. from Josh Bernoff's blog by defy+god · · Score: 5, Insightful

    He concludes with this statement in his blog:

    "Finally, a word for Apple. Apple is extremely stingy with information about their business and public comment. Their unwillingness to comment on the record or off about anything they're working on or any industry results beyond the basic statistics fuels speculation, pro and con, from their supporters and detractors. In the research business we like facts -- and every other technology company is more open with them. So maybe it's time for Apple to share a bit more. When the real bad news hits -- and it's inevitable, no company gets everything right -- that openness would pay off."

    To a degree, he has a point. With Apple's secrecy, articles like these are run without having all the facts. Sensationalism becomes rampant. Then he has to go and say "In the research business we like facts." All too often we read more about speculation rather than facts from these research companies. They complain secretive companies like Apple or Google don't give them enough information, but I wonder where the actual "research" in research business has gone.

    --
    hackers of the world unite!
    1. Re:from Josh Bernoff's blog by wass · · Score: 3, Insightful

      In other words, they're complaining that Apple doesn't regularly fly these guys out on a free 'vacation' to Cupercino, feeding them luxurious 5-star dinners and hosting them in 5-star resorts, to rave about their latest vaporware hype, like other well-known software and hardware vendors do.

      --

      make world, not war

    2. Re:from Josh Bernoff's blog by MrMickS · · Score: 3, Insightful
      Why research? Research is hard work. You have to check things and find corroborating evidence. Its much easier to get hold of a bit of data, slap it into a spreadsheet, draw a few graphs, then make statements based on what you see.

      Seriously, why would Apple release real data to these people when they see what they do with the data that they can get hold of?

      --
      You may think me a tired, old, cynic. I'd have to disagree about the tired bit.
  8. Credit Card data by failedlogic · · Score: 3, Interesting

    A few readers commented when the story was posted yesterday that they were wondering "How" the credit card data was obtained. It seemed from yesterday's story and the posts that Forrester Research had obtained credit card detailed transaction lists (w/o the credit card numbers, etc, I hope!).

    So, I would like to ask, how was the data obtained and is this level of detailed information avilable for legal purchase? I'm just curious as to how much information is available about credit card puchases.

  9. He should not be pummled by soft_guy · · Score: 2, Funny

    He should take a hit on credibility. He maybe should be fired. But I agree that physically injuring him is probably more than he deserves.

    --
    Avoid Missing Ball for High Score
  10. Mark-et Their Words by Doc+Ruby · · Score: 3, Insightful

    I've been reading Forrester, Jupiter, IDG and other pundit research papers for over a decade. They're almost always just rationalizations of some preconceived notion, some foregone conclusion that their methodology reinforces. I don't know if they plan it, or if marketing people just can't tell science from "Tang". But I don't know why anyone reads these reports expecting anything but a blast of conventional wisdom.

    Which is, of course, why everyone just takes what they write and run with it. That's the measure of success at marketing research peddlers. It's the CIO self-perpetuation. One reason why so little ever gets done right, but so much does get done without being called wrong. To blame their own market for taking them seriously when they ought not be is finally a whisper of honesty from these chattering weasels. I expect them to fix that in the next release.

    --

    --
    make install -not war

  11. Re:Look at the trends here ... by Divebus · · Score: 3, Insightful

    "Look at the trends here"

    Yes, there was a massive spike last Xmas that hasn't been exceeded during the 11.5 months that followed. Indeed, if you draw a line from that peak to the present, iTunes queries are down from a year ago. It's proof positive - especially if you don't know a fucking thing about statistics!!

    I can't find my ass with both hands around statistics and even I can see what's wrong with Forrester's report. So, Forrester my ass.

    --

    Most of the stuff on /. won't survive first contact with facts.
  12. Sample size was probably ok by Dcnjoe60 · · Score: 2, Informative

    Actually, the sample size of 1,000 was probably fine, or at least it would have been if they had used a truly random sample of credit cards. However, it is evident from their results, that they didn't. The failure was in trying to extrapolate results from data that wasn't statistically valid.

  13. Welcome to America by plopez · · Score: 3, Funny

    Where your information belongs to everyone but you.

    --
    putting the 'B' in LGBTQ+
  14. Testimony of Mr. Marc E. Kasowitz... by mpaque · · Score: 4, Interesting

    From the testimony of Mr. Marc E. Kasowitz before the US Senate Committee on the Judiciary:

    One particularly effective illegal strategy involves the
    following scenario: the short-selling hedge fund selects a
    target company; the hedge fund then colludes with a so-called
    independent stock analyst firm to prepare a false and negative
    "research report" on the target; the analyst firm agrees not to
    release the report to the public until the hedge fund
    accumulates a significant short position in the target's stock;
    once the hedge fund has accumulated that large short position,
    the report is disseminated widely, causing the intended decline
    in the price of the target company's stock. The report that is
    disseminated contains no disclosure that the analyst was paid to
    prepare the report, or that the hedge fund dictated its
    contents, or that the hedge fund had a substantial short
    position in the target's stock. Once the false and negative
    research report -- misrepresented as "independent" -- has had
    its intended effect, the hedge fund then closes its position and
    makes an enormous profit, at the expense of the proper
    functioning of the markets, harming innocent investors who were
    unaware that the game was rigged, and damaging the target
    company itself and its employees.


    http://judiciary.senate.gov/testimony.cfm?id=1972& wit_id=5486

    Student exercise: Compare and contrast with the movement of AAPL stock shares before and after this report came out.

  15. That's not the case for rare phenomena by Solandri · · Score: 4, Informative
    The 1/sqrt(N) 95% confidence interval is only safe for common phenomena. That is, if the frequency with which you measure something is in the 10%-90% range (or thereabouts). As you get to either extreme, the confidence interval remains the same, but its accuracy in terms of raw numbers decreases.

    For example, if your sample is 1000, your 95% confidence interval is 1/sqrt(1000) = +/-3%. So if your 1000 samples showed 250 occurrences, you would know that it's 95% likely that the frequency of occurrence is between 22% and 28%. So the real frequency could be between 220 occurrences or 280 occurrences per thousand. No big deal for year to year comparison purposes. Worst case a 50% drop in sales is measurable because one year you could've been low (220), and the next year high (280/2 = 140), and the change is still statistically significant (outside your confidence interval).

    For rare phenomena, this runs into a problem. Say the frequency of occurrence is 0.1%. You take 1000 samples and you measure 1 occurrence. The neophyte statistics student will say "Cool, I meansured 1 occurrence +/- 3%, so I have 95% confidence that the actual rate of occurrences is between 0.97 per thousand and 1.03 per thousand." Unfortunately, that's wrong.

    The confidence interval is based on the percentage you measured. Your confidence interval says there's a 95% chance that the actual frequency of occurrence lies between 0% and 3.1%. There is a huge, huge difference between 1 incident in a thousand and 31 incidents in a thousand, especially if you're trying to compare between two samples. One sample (year 2005) you might get 25. Next sample (year 2006) you might get 5. These are both within your confidence interval, but if you're not careful you would erroneously conclude that you have 95% confidence that sales plummeted to just 20% that of the previous year.

    Put simply, if you want to accurately measure rare phenomenon, your sample size has to be large enough that your confidence interval is significantly smaller than the rate at which that phenomenon occurs. If iTunes sales account for 0.1% of all credit card sales (which I think is a very high estimate) and you want to compare year to year changes, you probably want an accuracy of at least 1/10th the 0.1%, or a margin of error of +/- 0.01%. Your sample size needs to be large enough that your confidence interval is around the 0.01% range. That is, you need a sample size of a 100 million credit card transactions.

  16. Wait, they did this *how*? by pla · · Score: 3, Insightful

    based on a random sampling of 2,000 credit card accounts,

    Ummm... Now, I harbor no delusions that my credit card history really counts as a secret - Obviously my CC company has it and uses it to market bizarre crap to me, and they'd turn it over to the government without thinking twice about it.

    But how does some guy just go and "randomly sample" 2000 cards' histories? If I wanted to validate his study, could I do the same?


    Something doesn't seem right here, and I don't think most people would like the "how" either way.

  17. Can the editors while your at it. by SgtChaireBourne · · Score: 2, Interesting

    Seems to me like a pretty clear admission that the sample size is too small to be reliable. He took the data he had available, analyzed it, and presented the results while noting the deficiencies in the method. Doesn't sound much like fraud to me. That's just grade school reading by the way...

    So in other words, he knew from the beginning that he was spewing out bullshit. The article never should have gotten past the editors. One can argue back and forth whether the journalist should be disciplined, I'd argue for it and for an investigation of possible conflict of interest, but there's no way the editors should have let the article through as it stood. They should have been canned.
    --
    Beta is broken and the link to classic doesn't work. Stop wasting our time or there won't be anybody left here.
  18. This just in... by Skyguard · · Score: 2, Funny

    a new study shows that studies are not factual at all and are used as propaganda by large powerful companies.

  19. truism once again proven by chelanfarsight · · Score: 2, Funny

    there are three kinds of lies in this world: lies, damn lies, and statistics.

  20. Re:You're taking it out of context by lendude · · Score: 2

    No, I don't think you are an exception - that's the same meaning I took from the most specific reading of the sentence. However, I'm saying that I see no point in even mentioning a "real drop" in their sample data when it simply can't be extrapolated to sales as a whole, especially in a research document they are flogging: to me it appears to be a triumph of marketing over valid conclusions. "Gee, look at this dip! (PS. oh, but don't take any notice of it please!)". Cheers.

    --
    "Get off the cross - we need the wood" - Tori Amos
  21. Thought it would be fun to compare by mschuyler · · Score: 2, Insightful

    I thought it would be fun to compare slashdot comments to the previous posting to see how many geniuses out there fell into it with "I told you so," "It's because Apple is a big meanie," "Songs are no good," and similiar contributions. But I have to say after reading through the previous posting's comments, though there were a few like the above, the vast majority of slashdotters called it correctly and said the previous study was flawed, giving all the reasons why. Impressive!

    --
    How about a moderation of -1 pedantic.