Sony's backing the Vita's US launch with a $50 million marketing campaign. The company is, as you would expect, bullish on the system's future here, with CEO Jack Tretton estimating a big impact in terms of launch window sales.

Speaking with Reuters, Tretton said he would "be very pleased" if the PlayStation Vita moved half a million units in the United States in the next three weeks. Even though the Vita moved 321,000 units in its first two days on sale, it took over a month for the Vita to hit 500,000 in Japan. The cheaper PSP is still popular in that region and moves thousands of units each week. North America, however, is a much larger market.

Instead, launch sales of the PSP in the US may be more indicative of what the PS Vita will do. The PSP launched here on March 24, 2005, for $249 and sold 500,000 in its first two days.

This article was originally published on Joystiq.