Uni Watch, a blog devoted to sports uniforms, has
an excellent (and very long) breakdown of logo creep in sports. It's specifically addressing the the kind of branding that Reebok has on NFL jerseys (a logo on the upper chest) rather than the more ostentatious branding in something like Nascar. I'm not entirely sure where I fall on this debate, as I see the merit to both sides (teams/leagues have an opportunity to capitalize on their audience while fans pay quite a bit in money and attention to watch their favorite team.
I found this analogy especially troubling: "Let’s say American Express offered to give the state of Illinois a huge sum of money targeted for the state’s school system  but in return, the AmEx logo would have to be printed on the statehouse dome, AmEx ads would have to be posted throughout state facilities, and the state itself would have to be renamed “American Express Presents Illinois.� Would that be a good idea?"
To be honest, I'm not sure I'd be against any of it . . . At least I could easily argue both sides.