While RSS could help media titans sell more ads and keep users loyal, the technology could undermine the giants, too. RSS levels the playing field between upstarts and the established media, since news readers don't distinguish between blogs like Gizmodo, which covers consumer electronics, and publications such as PC Magazine. Some believe RSS could make online media even more fragmented than it is today, setting off a struggle for ad revenue. The biggies claim their brands will insulate them against upstarts. Says Catherine Levene, vice-president for product, business development, and strategy at New York Times Digital: "We think people will still come to [our site] for our editorial judgment."

So far most online merchants haven't embraced RSS. But the potential exists for Web stores to alert customers that they now have that snazzy blouse in aqua. Web-savvy outfits, including Amazon.com (AMZN ), Apple's iTunes Music Store, and the Netflix DVD-rental service already use RSS to alert customers to new music or movies. Analysts expect travel, apparel, and financial sites to start testing the technology early next year.