RIM posted a 33% increase in its 1st quarter net income compared to the first quarter of 2008 that reported a total of $482.5 million. The report has it that RIM hurdled the 94% estimate by the analysts. Meanwhile, Jim Balsillie, RIM’s CEO, disclosed that the U.S. smartphone market grew to 55 percent from 40 percent in the previous two quarters, and that it added 3.8 million BlackBerry subscribers in the first quarter, bringing its total subscribers to 28.5 million.