The program, which Google introduced Friday, is aimed at Web sites that participate in its AdSense network. With AdSense, Web publishers agree to run text and banner ads brokered by Google and share per-click revenue with the company. Google ensures the ads are relevant to the site's content via contextual ad-matching technology.
Now Google will reward AdSense participants that refer other small Web publishers and bloggers to the program. The company will pay $100 per AdSense sign-up after new participants earn their first $100 in ad revenue, the company said. Publishers can join the program by adding a "referral button" to their sites through their AdSense accounts.
Google will also pay AdSense participants in the U.S. $1 for every person who downloads the Google Firefox toolbar via referral and was not a previous Firefox browser user. In July, Google of its toolbar, a browser add-on that incorporates spell check, search and other features. Previously the toolbar only worked with Microsoft's Internet Explorer.
Forrester analyst Charlene Li compared the Firefox deal to, which makes Google's toolbar a standard component of Sun's Java programs. That's a real coup for the Mozilla Foundation, which develops Firefox, she noted.
"Firefox has long encouraged its base to include graphics to promote others to download Firefox. But Google's AdSense now gives it an opportunity to pay site owners to do this, which will only further encourage Firefox's marketing and distribution," Li wrote in her blog. "While it's not officially stated, it's pretty clear that Google is footing the bill."
AdSense is an important source of revenue for Google, accounting for 43 percent of, or $675 million. Yet the program is facing new competitive pressure. Yahoo launched in August, aiming to make a dent in Google's business.