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Does SPAM Peak on Wednesday?
danlor asks: "After installing a pretty good spam filter here at work, we noticed an interesting weekly trend in overall spam intercepts. They peak on Wednesday and trough o n Sunday. It is an almost perfect bell curve. We have gone over this quite a few times here, but cannot come to consensus on why this would be. Could Spammers really be God fearing? Why would Spammers have a 'hump' day?" Has anyone else noticed this trend?
Got any graphs or anything compiled from your findings?
Or maybe they do things on the weekend, like normal people? And don't feel like getting much work done on Monday, like normal people?
:)
I bet if you graphed legitimate business email, it would show the exact same trends.
Spammers are people too, just barely.
I've had enough abrasive sigs. Kittens are cute and fuzzy.
Analyzing 11,560 spam emails that have come to my inbox over the last few years, here is the distribution over the days of the week: (What a pain it is to get a graph to reproduce correctly on slashdot!)
While it does show a "bell" with a peak on Wednesday and a dip on Sunday and Monday, it's certainly not significant. 20% less email on the lowest vs. the highest day isn't significant in my mind.
(Statistics generated with MailListStat from freshmeat.
Many people don't read their emails the weekend (workers, students, etc.). So, it's typical that a monday morning in-box is always almost full.
Many people I know, keep cleaning their inbox until tuesday indeed! So, Wednesday might be a safe day for spamming, as inboxes are emptier.
There was an article about an email marketing conference (the legit kind) on Wired news a little while ago - maybe last month? It said that response rates for discretionary spend products were highest on a Thursday. I imagine that if so, spammers know this too, and are sending out on a Wednesday to be in your mailbox Thursday AM.
Don't worry, he didn't leave with his kneecaps.
But before I uncapped him, I was able to glean this much about their mailing habits: apparently, whether true or not, there is a prevailing idea in the spam community that Wednesday mid-morning is the best time to send spam.
There idea is that this maximizes the likelihood of it being read; they consider weekends not to be important because people are occupied with funner things than spam; they consider Monday and Tuesday to be "warmup" days into the week, when people may actually be doing work. Thursday and Friday they consider "slackoff" days in which people not only don't do work, but don't read email either. So that leaves Wednesday. And if you analyze your logs further, I bet you'll find that the peak within Wednesday is mid-morning, not the grogy, naptime after lunch hours. That's what I see with my filter, anyway.
It's all going according to
I've been saving most of my spam for the past year or so. A quick scan of my spam folder shows the following breakdown, sorted by frequency:
Or, for the same data as a histogram (line length divided by 25):
Wednesdays are pretty much in the middle of the range (the mean is 824.9).
The bigger trend I've seen was a big spike back in May, but the rate has sloped off considerably since then, as this chart of month over month spam trends shows (line length is again divided by 25):
(The script that generated this is available on request.) A major cause for this change in trends may be a change in email address around then, but even before the switch I was seeing a dropoff in the number of spams I was receiving. If this pattern is more general than just my mailbox, I have no idea what's causing it.
Disclaimer: no general trends are implied, this is just "back of the envelope" analysis of the spam mail I personally receive. As noted above, if anyone wants the shell scripts that generate these charts, you're welcome to them -- they're just a few lines of Bourne code that scan over my mbox mailboxes. If you use something other than mbox mail storage, the script may or may not do you any good, but if you want it, ask. :-)
DO NOT LEAVE IT IS NOT REAL
I've noticed the Wednesday peak in the accounts attached to my business. Those are primarily the inkjet cartridge, diploma, "forbidden CD," prescription pharmaceutical, hot stock tip, and those obnoxious idiots at Logosaurus. In other words, the spam has a higher "tone" if you will.
The spams to my Hotmail account spike on Friday evenings. Those are what I would call the "dregs of humanity" spams--the assorted barnyard animals, herbal enhancements, and general "Are you lonesome tonight" spams. They're also more likely to be inept, such as having a "TO" field that reads "C:\documents\addressfile.txt" or words to that effect.
Bagnallb at AOL is sort of my own personal spammer (although I share him with many other people on the greater Internet). He really, really wants to take over my domain, and he manifests this by increasingly frenetic efforts to find an obsolete version of FormMail. He's been trying without success for six weeks now, and his efforts always, always increase on Wednesdays.
So I'd say Wednesdays for the "business class" spam and Fridays for the really scummy stuff. Bagnallb is scummy, but he's a Wednesday sort of fellow.
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