Even if they start as inconspicuous ads, they won't stay that way. The advertising industry cannot be trusted, it won't be long before you're solving captchas inside ads to dismiss them from the screen.If it blends in the background, like say a billboard, then I won't mind. Plenty of games have had ads or product placement integrated in an inconspicuous way.
But if it's like a banner on the bottom that doesn't go away or you're forced to look at them? No, eff that noise.