The Atlanta Journal Constitution carried a story saying that a lot of news sites, with the exception of USA Today’s parent Gannett were moving to required registration. Now, USA Today says it’s testing registration, asking for gender, zip code and year of birth.

How reliable is this self-reported data? I lie on site registrations unless there’s a compelling reason to tell the truth, and I’m not alone. A friend of mine tries to get this fellow Safeway customers to trade discount cards with him simply so he can dirty up their database.

On a lot of sites, the most populous zip code is 90210. That might be a good way to test the quality of a registration database. Divide the percentage of the Internet population that’s in 90210 by percentage of the site’s population whose zip code is 90210 and multiply the result by 100. The closer a site’s index is to 100, the higher the quality of its self-reported demographics.

Any advertiser that accepts self-reported demographics on required-registration news sites is guilty of professional malfeasance.