I've watched Giovinco several times, and he thrives in smaller club, actually he's a great player for those type of clubs. I just don't see him cutting it at a top side. besides, not a lot of teams showed interest in him barring Parma, right?
Back to topic, Tevez is 20 times the player Giovinco is, doesn't matter if the latter has had a good what? 4-5 good games this season?