A Bloomberg report says that Google has successfully tested ads on mobile phones in Japan. Deep Nishar, Google product manager, suggests ads on cell phones might be priced higher than the web because users are closer to making a purchase.

The piece suggests, but does not say, that ads are being delivered as part of Google’s mobile services. The company offers both mobile search and mapping services in the U.S., but Nishar tells Bloomberg it’s still too early to monetize mobile in this country.

“We believe this is a phase when people should be investing in the market as opposed to trying to harvest something that isn’t quite there yet,” Bloomberg quotes Nishar as saying.

Competitor Yahoo! has done tests of text ads in the UK.

via clickz