Epic Games co-founders Tim Sweeney and Mark Rein revealed that iOS game Infinity Blade is the company's most profitable game ever, if you look at it on a relative scale:
But the cost of creating, marketing, and distributing Gears of War, for example, and monstrous. And when you look at a strict scale of dollars spent versus dollars earned, Infinity Blade is at the top.
So yes, Epic co-founders Tim Sweeney and Mark Rein have gone on record as calling the iOS title the "most profitable game we've ever made."
Now of course, Epic could not exist if it only made games like Infinity Blade. If you spend $10 to make a game and earn $50 in sales, but another game costs you $1 million to make $3 million, no company in the world is going to choose the former.