Anytime I notice an overtly blatant product placement (e.g. 3 second shot of a logo), I feel like I discovered a mole (as in double agent).

There's a certain feeling of "Gotcha! I still got it. Can't full me, Diet Coke".

Also good shows and movies do not do this. Never once noticed product placement in The Wire or Breaking Bad, Pontiac Aztec notwithstanding.