Strategy Analytics has predicted that the Apple iPhone, which is outperforming the RAZR's launch, could become the best selling mobile phone in the U.S. in three to six months, according to Forbes on Thursday.

That prediction by SA's Barry Gilbert was based on phone sales data, the iPhone rate of growth and the fact that AT&T recently revealed that the iPhone is their best selling mobile phone.

"The iPhone has momentum that is basically unparalleled," Mr. Gilbert said.

Currently, the RAZR v3 family has 16 percent of the U.S. market. The next best sellers at the LG Chocolate sand LC VX8300, according to iSuppli. The iPhone currently has 3 percent of the market. However, the market share of the RAZR is eroding. "If you add up all the RAZR products, it's still the leading family," said Mr. Gilbert. "But if you look at any given model, like the v3, the iPhone seems to have surpassed that."

In terms of launch success, the RAZR sold 750,000 units the the first 90 days after launch. The iPhone has soled about 1.4 million. In terms of profit, Apple makes four times the profit on each iPhone compared to the RAZR. Finally, the Apple iPhone is picking up speed thanks to the price cut.

As a result, if Apple were to sell 1.7 million more phones in calendar Q4, that would put it at number one. "The iPhone was originally viewed as a niche product," said Gilbert. "But its design, features and functionality are turning out to have broad appeal."