The first thing is the game fell into the shadow of it's predecessor, and game that while selling over a million copies, failed to impress reviewers. The second issue might be that 50 Cent isn't quite as popular as he once was, and even though the name is recognizable, many gamers scoffed at the idea of picking up a game starring him as the hero.
Blood on the Sand has sold an estimated 56,000 copies in the U.S. between its February launch and early April. In its first two months of release in the fall of 2005, Bulletproof - Blood on the Sand's prequel, sold 681,000 copies, with life-to-date sales of 1,123,000 units according to NPD. Quite the difference in numbers.
Kotaku takes a look at a few more reasons why the game sold so low, and even mentions that maybe Activision's decision to sell of the title might have been a pretty smart move after all. (Though we still can't say the same about Ghostbusters.)
Lets hope THQ drops the price of the game to a more wallet friendly $40. This should help spur some sales, because really, everyone deserves to find their diamond encrusted skull with a friend in co-op.