Burn, Zombie, Burn! Was Released Via Sony's "Pub Fund" Scheme.

Essentially, the program matches a PSN game's production costs in royalties, in exchange for PS3 exclusivity. It's something which Burn, Zombie, Burn! devs have touted as "invaluable".
James Brooksby, studio head of Doublesix, spoke to other developers, saying, "I think there's a number of other ways in which the Pub Fund can help you, not least because Sony suddenly has a more vested interest in your product's success." Since Sony is looking for a good return on its considerably sizable investment, not everyone can get on the Pub Fund. "Obviously there will be a level of quality expected from Sony's side, so not everyone will be suitable for Sony either," said Brooksby.

"We put a lot of money into the marketing of Burn Zombie Burn," Brooksby said. "And our own funding, along with Sony's, helped achieve great exposure for the game."</blockquote>

He concludes by stating that the team have been "absolutely delighted" with the sales of the game so far. If you haven't got the game yet, you really should. It's great fun, as our review confirms here.