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.

Depends a lot on implementation. My example: Netflix at the beginning of shows sometimes says something to the tune of "contains product placement". Several times now once gotten to the end and notice that it didn't stand out to me. It makes me suspicious, was it there all along and I just got advertised to without noticing it? Was it not there this episode? Am I becoming complacent and not noticing product placement as much as I used to?