And it should also be noted that third parties have had more success with publishing Wii software than PS3 and 360 software. Supporting the Wii has probably been the only thing keeping Sega afloat.
I'd say it's fair to assume that the average PS3 and 360 title needs to sell over 500K before making a profit and the average Wii title only needs to sell over 250K before making a profit.
Just have a look at the amount of PS3 and 360 titles that have sold less than 500K, some of you may be surprised.
And when you consider how prevalent piracy is for the platform an attach rate of more than 8 games per console is pretty impressive tbh.