For some insight into the ruckus that SoftBank kicked up when it relaunched its mobile phone service with a zero-yen-per-call plan, check out its new ads and compare them with the competition's. NTT DoCoMo's ads showcase no less than seven famous personalities (eight if you count female comedy duo Othello as two), each one representing a target demographic. KDDI's au ads augment popular actress Yukie Nakama with ubiquitous hunk Mokomichi Hayami and a subset of minor but recognizable TV talent.

SoftBank's ads feature only one celebrity: Cameron Diaz. And while DoCoMo's ads stress continuity and reliability ("That's why I'm DoComo"), and KDDI's make a big deal out of its wide variety of features (each talent represents one), SoftBank's give you nothing but Diaz. There's no pitch, no explanation, no jokes. In one, Diaz is in a supermarket, her basket overflowing with stuff; in another she looks businesslike, striding purposely toward the camera. In both she's talking on her cellphone, and in the print ad she just stands there with the phone to her ear, staring straight at you.

The implication is simple: "We got Cameron Diaz and you didn't." It's a move that's as cheeky as CEO Masayoshi Son's shock announcement of the zero-yen plan the day before the start of "number portability" on Oct. 24, which allows cellphone users to switch carriers without changing their telephone numbers.