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Analysis of Netflix's DVD Allocation System
dvd_rent_test writes "Netflix uses the number of movies you have previously rented to determine your priority in getting movies. The more movies you rented during your last billing cycle, the less chance you have of receiving a movie versus an individual who has rented fewer movies. This is why new users have great success getting their movies and older or heavy users have a difficult time getting some movies."
Many businesses do this. They rely on new customers, not repeat-customers. Kinda like BMG music, etc. This isn't rocket science.
I was wondering about this. I have been a member for almost two years, and I am very efficient about sending the movies back quickly (thus maximizing the total number of movies I can see.) I have been wondering for a long time why I never seem to get any of the "Short Wait" movies, much less the "Long Wait" ones. Well anyway, I'm thinking about cancelling Netflix anyway. The post office has lost (or stolen) a number of movies I've sent back anyway. I'll probably just get a PVR instead.
I thought it was just a coincidence that I (with a newer account, not many rentals) got the same movies my mother(very old account, lots and lots of rentals) couldn't get. Kinda stinks really... good thing im in the dorms at college so I get to change my address/CC/account every 6 months :)
(This Space For Rent)
I had to stop using NetFlix a couple months ago because my USPS carrier wouldn't consistently put them in my apartment's mailbox (leaving them outside risking theft--those big red & white envelopes just scream FREE DVD!).
When I went to kill my membership, they offered me the same membership for less money, what was 3 DVD's for $20 a month, was now two or three bucks less. And the savings could be had on all there other plans, if agreed to use their services for a year or so.
Seems like they've got some pretty "creative" ways of handling their customers. I'm content buying DVDs off of eBay.
Anybody else think they're a little "funny"?
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety
Could this result in people continuously generating new accounts? This would be a potential nightmare for Netflix.
(insert sig here)
I had a similar experience with Netflix. A bunch of current releases were listed as long wait or very long wait. I complained to Netflix and amazingly that day the status changed from long wait to short or available now. Coincidence? I thought so originally but this report sort of sheds new light on things.
You don't get screwed over, you just can't get high demand movies as readily as someone new customers.
Besides if you want to watch movies that bad, go out and buy them. Most movies are available at below cost the first days after release.
Beer Die is the game of champions Learning To walk my own path.
It's not so far fetched. I wanted to watch the Buffy season 1 DVD. Disc 1 was in my queue for 6 months! and status never changed from very long wait! I got fed up and downloaded the episodes.
The thing that kills me is that Netflix apparently doesn't take into account the number of movies you can check out at a time (it costs more $/month to get more movies at one time). So as this clever analysis points out, if you pay more to get 5 movies at a time, then you are more likely to never get popular movies.
It seems that a better algorithm would normalize the number of movies rented in each billing cycle by the number paid to be rented at one time.
I know this may be slightly off topic but there is a company in the UK which runs a similar service to NetFlix, called dvdsontap.com I;ve used them for about 6 moths and they have been very good, including not giving me any hastle when a dvd they said the had send did not turn up.
Alos as far as I am aware the dvd queues are the same for all users, so you may wait a bit for new relases but most other stuff comes as soon as it gets to the head of your rental queue.
If you read a speed reading book, does it take you less time to read the second half?
I mean.... you crap all over your good, old established customers in order to attract new ones... seems to me the old customers should get the preferential treatment and the new ones should get to sit and spin for awhile. Whatever happened to loyalty?
It seems more fair to me to just have it be first come first serve. If you click the link first, you get in line for the movie first. If you reorder your list, you just stepped out of line, no cuts.
You're partially right...but it has everything to do with the trial period...
During the trial period, you have an empty history. Therefore, you get every movie you want (almost) immediately. After you do this and start thinking the service is so awesome in terms of title availability, you continue and, as long as you are trying to use the service to get movies you want (as opposed to being a dormant subscriber who pays but never gets anything), you get screwed because you'll continue to get punished for wanting to take maximum advantage of the money you're spending.
Why do I h8 apple?
I don't know how well it's doing as a business, but there are many advantages to renting from Netflix rather than the big chain stores. They let you keep movies as long as you want. They have a far larger inventory than any brick and mortar store. Blockbuster is great if you're looking for domestic new releases, or you need to rent something in a hurry, but they blow half-digested-popcorn-chunks if you're looking for foreign or old (and by old I mean, older than a couple of years) movies.
Plus they actually have NC-17 stuff. Most Hollywood and Blockbusters won't rent those, or carry only censored versions. Personally, I prefer to be treated like an adult.
The only problem with this is if you wish to watch a series of DVDs. I tried to watch the entire 3 seasons of the Sopranos. I finished them a month ago, but never got Season 2, #1. It was first listed as 'short wait', three weeks later, it went to 'very long wait.' I'm still waiting, and its still 'very long'. The same seems to be true with '24'. Disc 1 has always been 'very long wait', but 2-6 are available 'now'. I wish they'd fix that.
The problem I have is that the allocation scheme is not documented and not uniform. More the undocumented part. When I was researching this on USENET people indicated that Netflix customer reps told them the allocation method was completey random . I have not contacted Netflix myself. It is far from that.
I think it has more to do with keeping the light users who pay as much as the heavy users happy so they don't cancel and go to Blockbuster. And of course to keep the new users very happy.
I tried not to editorilize too much in my report I feel more comfortable guessing here.
I was a Netflix subscriber for a few months. My experience matches the study - there was a slow buildup of "long waits" in my queue. Eventually, when all the movies I wanted to see were "long waits", I cancelled.
In general, I find that I'm getting a lot more aggressive with cancelling subscriptions or services, especially if these services involve new technology. Cancellation is the only message that is received - all others fall on deaf ears. Sprint PCS, for example, has an customer service voice recognition system that will route you to a service agent if you say "I want to cancel". Any other message is handled by an automated, worthless system. I was able to negotiate a much better rate with them by using those four magic words.
For example, if you only rented one movie last month, then this month you would have good rental availability. If you rented a lot last month, then this month you would have crappy rental availability.
So the solution is two accounts, alternating between each on a monthly basis?
Michael
There is no cryptographic solution to the problem where the intended receiver and the attacker are the same entity.
Netflix are spammers, they abuse their most frequent customers by not shipping them DVDs, and I can go down to Blockbuster and rent DVDs RIGHT NOW.
Remind me again, why would I do business with Netflix?
www.eFax.com are spammers
They don't track it by that, it's by email. I have let my netflix account lapse twice now, and restarted twice. One time I started with a different email address and made a new login, and it didn't "know" about any of my old rentals. The other time I used my old email and login and it did know about them.
My wife and I used to rent 10+ movies a month on the standard 3-out plan. But then we got busier and started watching less and less. Lately we've been lucky to watch 2 or 3 movies in a month, and a few recent months have only seen one. We switched to the 2-out plan sometime last year to save money. I later realized that this plan is not normally offered - our account got flagged and we were offered the plan based on our rental history. Netflix kept a customer and we stayed happy by paying less.
My sister-in-law's story is even more phenomenal. Her financial situation dictated that she cancel completely, which she did. Netflix came begging to get her back, and ultimately agreed to keep her on for a mere $7/month! (I thought it was $7 for 6 months, but this sounds more likely) She's a damn good haggler, so I don't know if this would be common at all; I imagine if they did it too much, they would lose money.
I've always been impressed by the fact that we've been able to get just released movies very quickly. I suppose maybe that's one reason we haven't canceled despite not getting as much out of the service lately. When we do use it, it's always top notch, so Netflix still gets our money. I don't recall having major problems even when we were renting a lot more, but I suppose Netflix has grown considerably since then. I always assumed they kept the service good by expanding to meet customer demand. It'll be interesting to read more comments and see how other people's experiences relate to the study's results. I'd love to see the same thing conducted again with a larger sample size.
Say hello to zMac.
Just call up your credit card company and ask for a chargeback. Tell them you didn't authorize that amount of debit. Merchants hate that. It costs them money, and if it happens enough they can get investigated for fraud. If more people did it, Netflix would think twice before trying crap like that again.
This post expresses my opinion, not that of my employer. And yes, IAAL.
Hell yes, libraries kick ass.
I can access the card catalog system for my county-wide library system online (via telnet or the web), peruse their selection at my leisure (including DVDs and videos from every public library in the county, not just the one 2 blocks from my house - and including items that are currently checked out and not sitting on the shelf), and place a hold on it. If it's available, it will probably be delivered to my local library within 2-3 days; if it's something very popular like a new release on DVD it could take a couple months. I can check the status of a hold, and it'll tell me my position in the queue (I'm in 59th place out of 148 current holds for My Big Fat Greek Wedding on DVD, which I requested about a month and a half ago). When an item is ready, I just walk in, hand them my library card, they hand me my movies, and I get to keep them for 3 or 7 days (depending on the policy of the library the item belongs to, which varies somewhat, and how popular the item is - new releases are generally 3 days). If I return it late, the fine is between $0.10 to $0.25 per day (again depending on the library it belongs to), which they're not picky about if I haven't got any change with me.
The disadvantage of using the library compared to Blockbuster or Hollywood Video is, unless the movie I want is available and sitting on the shelf (not very likely), I can't watch it today. The advantage is that it's free, and the late fees are trivial.
The only disadvantages of using the library compared to NetFlix that I can think of are, instead of delivering to my mailbox, I have to walk two blocks (or the library will mail it to me for a $2.00 charge if I want), and I can only keep it for 3-7 days before returning it (I can afford the overdue fines, but I don't like to deprive others who are waiting). The advantage, again, is that it's free (aside from fines mentioned above).
Does your local library kick this much ass? Maybe not, but give it a try, you might be surprised.
$x='S24;r)>63/* h@<5+oZ)32"5cz';$me='phroggy'x$];
$x=~y+ -xz+\0-Tx+;print$_^chop$me for split'',$x;
The idea that they might lure people into thinking that there low wait times when they first sign up and then swith later seems to fit with the "character" of the company.
I was a netflix customer early on, when you paid per movie and had just a week to watch them. Good service, and living in San Jose right near their headquarters ( the only shiping point at the time ) meant I could sometimes order a movie on the weekend and have it arrive Monday.
Then they paid spammers to increase their "market share". Not "opt-in" list guys, but the ones who sent to anyname@domain.com. I complained, they replied that they only dealt with opt-in spammers. I told them that I'd have remembered if I'd ever created an account with the email address "HowieIsAGayFuck@mydomain.com". They replied that out millions of spams sent, I was the only one who complained. No apology, never mentioned they'd stop dealing with the offending spam flingers.
So after 2 or 3 years with them I did the only thing in my power, I walked. I'd been getting DVDs every month, told all my friends, heck, even was in on a couple customer focus groups at their offices.
Me, I'm hoping blockbuster and Walmart with their new DVD by mail services squash them like a bug. The idea of a company doing well based on vile spam doesnt' sit well with me.
Isn't the classic scheduling algorithm in Unix similiar to this, where processes which use the CPU a lot will be slowly penalized so that other processes will not be starved?
Maybe a solution will be to have a dutch auction for movies: the highest bidder for a given title-instance gets it.
I did some further analysis on the author's data, and found that he made a couple of assumptions which I don't think are true.
I made a graph of the average availability score vs. the $/rental for each period, and got a nice,clean inversely proportional graph. That is, the higher you pay per rental (e.g. his mom was paying $10/movie during one period), the better your availability score. Where some of the data didn't *quite* fit (but was pretty close) was where the author (A) had rented fewer movies on his account during the first period due to signing up his wife, and his availability score got better. Well, it did get better, but not in line with a month-to-month average. If you extrapolate that he was probably renting at a similar high rate in the previous periods (a valid assumption, as he says as much in the article), and instead use a rolling average 2-3 previous rental periods, you get a perfect fit for all the data.
So, here are my conclusions:
#1, the availability is not ENTIRELY dependent upon how many movies you rented the previous rental period. It is actually a "rolling average" number of rentals over 2-3 previous rental periods.
#2, the author assumed it was based entirely on the number of rentals/period, but this is not true. Subjects who had upgraded accounts had noticably higher availability, but perhaps it was hard for the author to see this since he used the wrong figure of merit. The real figure of merit for Netflix is $/rental. After all, this is how they determine if they are losing money buy renting movies out to you.
The test subjects that were paying less than $2/movie were sucking it up with super bad availability scores, whereas the folks that had very low rentals and thus paid $10/rental, got much better availability. The actual curve fits an inverse proportional graph quite nicely, with the "sweet spot" being around $4-$5/movie. Even 6 rentals/period (with a standard $20 membership) still had very reasonable availability, but was on the high end of the asymptote.
And before someone accuses me of working for them simply because I like the fucking company...well...I don't. And you have to believe me because...well...I said so ;)
bad sig...no donut.
I've been a member for a rather long time (almost 3 years) but I don't watch movies very promptly (their records show that I've only watched and returned 11 films in the past 3 months). So I guess I fall into "we like thi$ cu$tomer" category.
;)
I just checked and I have 59 movies in my rental queue, and every single one of them is listed as "Now" availability. Granted, most of them are uncommon foreign and indie films so I'm not in competition with all those folks trying to get the latest "Austin Powers" movie or something, but still, having 59 flicks all sitting there at my disposal is probably indicative of some favoritism.
But back to the subject of shipping times. Personally I'm amazed at how quickly turnaround times are for me. I frequently will drop a disc in the mail on a Saturday afternoon, see it register with Netflix on Monday, and have my next disc by Tuesday or Wednesday. I never checked to see which center mine go to but I'm in Vancouver, WA if anyone knows off the top of their head..
So I don't think it decreases with time (length of membership).. I think it's more to do with the original hypothesis of number of films rented. I'm probably paying $6-7 bucks for each of mine now, but given the fact that I have a toddler and my wife and I both work, we're willing to pay that for the convenience. (I only make it out to the theaters a couple times each year).
I just did a quick test and stuck Solaris(1972) in my queue. Availability = "now". That's sad. Want me to rent it and send it to ya? As a new service emerges: scalping Netflix films...
In the Portland, Ore area and like card games? Check out: http://groups.yahoo.com/group/portlandgames/
but, I never have the problem of long wait times.
I've been a member since 2/2000 when it was 4-out for $15. They grandfathered me for many months but finally raised my price to $20, but still 4-out.
In this time I've rotated movies very quickly and only seen any kind of wait time just once or twice.
I did notice that following 9-11 the deliveries slowed to a crawl. Suddenly, the deliveries came the next day...and I noticed the return address very close to home. Now days, it's never more than 3 days turn-around to swap one movie for another.
But, here's the thing that might save me from the long waits. Possibly they use algorithms such as described, and possibly the algorithms don't affect me because of this... of our 4-out I only rotate 3 quickly. The other 1 is always something my wife wants to see, and she'll be busy and not get around to seeing it for a month or two. That one might throw off their trick.
Whatever... anything is better than Blockbuster...
Uhm, no, it can't.
People who spend the most money should at LEAST
be treated the same as people spending far less
money or no money at all, and under this system
they are NOT.
That hasn't been my experience. I live 1 day turnaround from the local center in San Jose. I drop my movies in the box, they get them early the next day (I've gotten e-mail about their recieving it before 7AM local time) and they ship out the same day with a new one.
Fantastic turnaround. And they love me this month because I have 3 disks I keep forgetting to send back.
The only time I saw a hesitation on sending was once when I had a long wait at the top of my list. I think they had an anticipation of return in the rental model that didn't happen that day.
But then again, I got a bonus rental (4 out at once) when they didn't have a copy of a movie locally and sent it from a different location to me. Great service.
I am not a resource! I am a free man!
I have been a member since August 2002. In that time, I have received three empty envelopes -- no sleeve or DVD. In each case, it was easy enough to figure out what movie it should have been. The last two were received unsealed at my local (podunk sized) post office. The postmaster says Netflix is well known among postmasters for sending out unsealed enveloped, the sleeves and DVDs fall out in bins, are collected, and periodically sent back to Netflix.
I don't believe the post office is stealing these. It would be so much simpler to steal the entire enveope rather than just the DVD and sleeve.
What really annoys me about this is that the shipping problems form has no choice for receiving an empty sleeve. If you report it missing and never arrived, they tell you to wait a few days and report it again. If you report it as scratced and unplayable, so they will send out a replacement immediately, they expect you to send the scratched DVD back.
Infuriate left and right