You know, that only 20% of games are worth playing, doesn't mean that they are the ones that turn profit. Rather the opposite.
Anyway, there are around 1100-1300 games released on consoles this gen (I am not including DS, as it alone has more games than Wii + Ps3 + X360).
~ 500 Wii
~ 400 X360
~ 300 Ps3.
I assume that ~ 1/3 games are Japanese developed.
So ~ 800 games, and 130-200 of them turned profit.
Normally, people assume that a Wii game needs ~ 300K to go profit (average of course, bigger titles need more, smaller need less) and a Ps360 game needs ~ 750K (again, average).
This would mean 80-100 games on Wii turned profit, ~ 30 on Ps3 and ~ 70-80 on X360.
Of course, you would have to exclude the Japanese developed, which would be almost 30 for Wii, 5-10 for Ps3, and ~ 15 for X360.
So 50-60 for Wii, 20-25 for Wii, 50-60 for X360.
So my point with this, is that Wii games needing 300K to turn profit and Ps360 games needing 700-800K to turn profit seems explainable.
Now, please point out the flaws in my analysis - I'm sure they are there.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS