Nobody likes a sell-out. Integrity has rarely been an issue for game developers who, by and large, are dedicated enough to their craft that they wish to uphold their artistic merit in favor of placating their corporate masters. It's a generalization, of course, but most game developers work for the love of the medium rather than to pad their pocketbooks. The hope is that they can achieve both by making the game they want that sells millions of copies. In-game advertising may just be the key.