(FORTUNE Magazine) – Calvin Klein Jeans started it all last year by laying out $1 million for a racy 116-page ad supplement to Vanity Fair magazine in which models displayed more flesh than fabric. Now copycats are teaming up with other magazines to publish their own raunchy ''outserts,'' as the thick supplements are called. At a cost of $300,000, Request Jeans, a little-known Belgian denim company, bundled a steamy 48-page outsert with the October issue of the men's fashion journal Details. The photos recount the adventures of two scantily clad women and the male hitchhiker they pick up -- the threesome mostly clothed in denim, to the extent that they are clothed. Now Revlon has forked out $1.5 million for a slightly more demure 68-page outsert in the October Vogue. The ads draw lots of free publicity. U.S. newspapers ran some 350 articles about Calvin Klein's ads, and the company netted free TV coverage equal to / about $11 million in prime-time commercials. Request's inspired 100 newspaper articles and global TV coverage. Advertisers won't say what the ads have done for sales, though, and some industry experts expect the answer is ''Not much for Calvin.'' But they do bring new brands visibility -- or notoriety. Says Laurie Zakreski, ad director at Request: ''I don't think that there are very many retailers who do not know who we are now.'' Collectors also can profit from outserts. Vanity Fair publisher Ronald Galotti says: ''I've been offered up to $500 for a single copy of Calvin's outsert.''