Why third parties fail:
Spyborgs
Because the game sucks
House of the dead overkill
Because the game sucks
Zack and Wiki
Because the game sucks (yeah, that´s right, i said it)
Dead Space Extraction
Because its on rails, and it sucks even at that
Mad World
I dont have any idea why. This game is amazing.
In the end, The Conduit is doing kinda well, 300k already, No More Heroes sold enough to get a sequel.
In the above list, you cant deny: all games sold poorly because they suck (except madworld). You cant blame a gamer for not buy Zack and Wiki: just look at the damn cover, or at the game genre, or all the terrible trial and error that last levels turn out to be.
Make good games. People buy em. Its as simple as that. There should be a Lol Cat telling publishers that!