Google is on a roll in Japan. On Jan. 24, the 800-pound gorilla of Internet search joined NTT DoCoMo onstage to announce plans to wed elements of Google’s search technology and other online services with the No. 1 Japanese wireless operator’s i-mode mobile Net service. The deal is the second major partnership with a carrier since the Mountain View [Calif.] company formally launched its Google Mobile services here with KDDI back in July, 2006.

By cozying up to the two carriers, which combined account for 80 percent of Japan’s 100 million cell-phone users, Google improves its chances of being the leader in mobile search. Though not everyone in Japan has a handset that works on the fast third-generation, or 3G, wireless broadband airwaves, more than 70 million DoCoMo and KDDI subscribers do.

It’s obvious Google’s brain trust isn’t just trying to rack up more search queries and e-mail traffic. Ultimately, they want a huge audience of cell-phone users they can target with online advertising relating to their searches. There’s lots of earnings potential in that: Worldwide mobile-search ad revenues could top $1.1 billion by 2010, growing seventeenfold from around $63 million last year, according to researcher eMarketer’s estimates.

Protecting the User Experience

And Japan will be a key early battleground. Consumers in Japan are just as likely to surf the Net from a cell phone while riding a train as they are from a PC on a desk at home. DoCoMo Executive Vice-President Kiyoyuki Tsujimura told journalists one of the goals of the tieup with Google was to boost DoCoMo’s shared search-related ad revenues to $94 million “as soon as possible.” [Executives from neither company would say how the bounty would be divvied up.]

Brace yourself for every e-mail, map, and Web page to be clogged with ads, right? Not so fast. Google takes a…