The Pew Internet & American Life Project has released results of a new survey of experiences with email spam.
The report’s headline is “The CAN-SPAM Act Has Not Helped Most Email Users So Far”, and this interpretation is followed by the press articles I have seen so far. But it’s not actually supported by the data. Taken at face value, the data show that the amount of spam has not changed since January 1, when the CAN-SPAM Act took effect.
If true, this is actually good news, since the amount of spam had been increasing previously; for example, according to Brightmail, spam had grown from 7% of all email in April 2001, to 50% in September 2003. If the CAN-SPAM Act put the brakes on that increase, it has been very effective indeed.
Of course, the survey demonstrates only correlation, not causality. The level of spam may be steady, but there is nothing in the survey to suggest that CAN-SPAM is the reason.
An alternative explanation is hiding in the survey results: fewer people may be buying spammers’ products. Five percent of users reported having bought a product or service advertised in spam. That’s down from seven percent in June 2003. Nine percent reported having responded to a spam and later discovered it was phony or fraudulent; that’s down from twelve percent in June 2003.
And note that the survey asked whether the respondent had ever responded to a spam, so the decrease in recent response rates would be much more dramatic. To understand why, imagine a group of 200 people who responded to the latest survey. Suppose that 100 of them are Recent Adopters, having started using the Internet since June 2003, and that the other 100 are Longtime Users who went online before June 2003. According to the previous survey, seven of the Longtime Users (i.e., 7%) bought from a spammer before June 2003; and according to the latest survey, only ten of our overall group of 200 users (i.e., 5%) have ever bought from a spammer. It follows that only three of our other 190 hypothetical users responded to a spam since June 2003, so that spammers are finding many fewer new buyers than before.
A caveat is in order here. The survey’s margin of error is three percent. so we can’t be certain there’s a real trend here. But still, it’s much more likely than not that the number of responders really has decreased.