The idea may prove to be a bonanza for publishers. By Drake Lundell, Associate Editor September 16, 2010 More and more magazine publishers are rushing to adopt new technology offered by the iPad and other tablet media devices by putting magazine content online. The trend is also opening up new opportunities for advertisers and presents another selling point for the tablet makers, too.With customers already accustomed to paying for software applications, charging for content can help media firms attract readers who rarely buy print publications. Charges vary. For example, each issue of Prevention, a healthy-lifestyle magazine published by Rodale Inc., is downloadable to tablet computers for $2.99, while its Runner’s World magazine costs $4.99. Rodale also offers Men’s Health and Women’s Health on the iPad. Sponsored Content Time Inc.’s People lets print subscribers download issues free with a special code but charges others $3.99, the same as the newsstand price for the print edition. Advertisement Other magazines available as apps on the iPad -- such as Sports Illustrated, Wired and Popular Mechanics -- offer some combination of the two models. E-publications are based on their printed cousins but contain many more layers of content, often in video form. The Rodale publications all offer at least six video demonstrations of products or techniques with each issue, and People posts hundreds of celebrity photos and videos with each issue. Advertisers are getting into the act by offering special sections made up of product demonstrations in addition to traditional advertising. Though magazine apps are still in their infancy -- the iPad was launched just last April -- subscribers seem to like the concept. Next Issue Media, a research firm, says that simulations it has done with early adopters show that magazines could boost their renewal rates as much as 9% by offering both printed and tablet versions. So far, media tablets aren’t yet a mass phenomenon. Only 11 million will be in the market this year. But by 2014, the number of such devices should swell to 50 million, making them ubiquitous enough for mass marketing.