...The magazines -- typically sports, music and entertainment publications -- say the extra cost and effort of screening their subscribers are worth it as a way to help insulate liquor advertisers from accusations that they are targeting minors.

Otherwise, they fear a rerun of the precipitous drop in tobacco advertising they endured a few years ago when cigarette makers, once a mainstay for magazines, scaled back advertising after coming under fire for targeting young consumers...

The magazines' approach for the liquor companies borrows a practice from general-interest magazines like Time Warner Inc.'s Time and Sports Illustrated, which sell advertisers various editions of the same issue with ads targeting readers according to income, job title, age, sex, and geographic area. They use U.S. census data and credit-rating agencies to cull information about their readers.

For the 21-plus editions, publishers start with the names and addresses of their subscribers and run them against up to three outside databases, including that of the credit-rating agency Equifax, to find readers who are 21 and over. For instance, Spin has identified a group of 256,000 subscribers, out of a total subscriber base of 478,000, who turn up in a database showing that they are at least 21. Vibe developed its program from a similar offer it had
created for Kool cigarettes several years ago, according to Publisher Carol Watson. Magazines charge a premium of 10% to 20% of an ad's price to cover the extra production costs and database search.