I am split on this issue.
I think ads in games can be done well, and it will actually make the game better, many racing games do this, billboards, sponsor flags, etc, along the racetrack can make it feel "real".
Even in-game radio could have a few ads, if they fit the game and didn't take themselve's seriously, like this:
Bediz said:
If we're flying through a city street in a stolen beater truck with the National Guard on our ass, it is hilarious to hear the radio calmly state "This block of songs brought to you by Ford. When you absolutely have to get the hell out of where ever you are, get Ford Tough!"
But I am COMPLETELY against ads that detract from the game, like the ads in (I think) a recent football game, (or was it a racing game? IDK), that actually slowed the game down, and detracted from the experience.