By Paul Carsten BEIJING (Reuters) – For all the hype, Apple Incs long-awaited iPhone agreement with China Mobile Ltd may deliver little more than a fleeting revenue jolt for the U.S. giant. A deal with the worlds largest mobile carrier, expected as early as this week, nets Apple 759 million potential new customers that could generate $3 billion in 2014 revenue, or nearly one-quarter of Apples projected revenue growth in its current fiscal year. But after the initial haul, Apple will find itself in a familiar, expensive battle with its main smartphone rival, South Koreas Samsung Electronics Co Ltd, to win over customers, one wallet at a time. And China Mobile will likely have to wait at least a year for its payout as it spends billions of dollars to build a 4G network so customers can make full use of their iPhones.