Well, here's a look at how much titles sold.
0-5K = unkown
5-50K = 147 titles (32% fail to reach 50K)
50-150K = 112 titles (56.4% fail to reach 150)
150-250K = 55 titles (68% fail to reach 250K)
250-400K = 40 titles (77% fail to reach 400K)
400-500K = 18 titles (81% fail to reach 500K)
500-750K = 18 titles (85% fail to reach 750K)
750-1000K = 15 titles (88% fail to reach 1M)
1000-1500K = 17 titles (93% fail to reach 1.5M)
1500-2500K = 9 titles (96% fail to reach 2.5M)
2500K + = 14 titles (3% reach 2.5M)
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS