Mobile devices are a new battlefield for the Internet in general, and for the advertising business that Google and many other players are striving for. The mobile Web has been hobbled by tiny screens, slow and unstable connections, and carriers' data-access fees, but a new era is coming, CNET News.com reported.

Apple's iPhone has shown that increasingly widespread Wi-Fi makes it possible to bypass mobile-phone network operators. And initiatives, like Intel's Mobile Internet Device and Google's Android, could lead it to a new generation.

Last week in a call, Google co-founder Sergey Brin expressed his optimism about the opportunity of mobile Web advertising.

"The mobile ads work very well. There's nothing to dissuade me it would be any worse than traditional desktop search," according to Brin.

Google's mobile image ads are similar to those on ordinary Web sites, but are smaller and are limited to one per page, the company stated.

Advertisers will pay only when an ad is clicked, CNET News.com reported.