I block any ads I can, ignore most I can't. Very rarely there are ads that can influence me. When I am walking somewhere, hungry, and I see a food ad, from all the ads I've seen, that is probably the only type that has the "desired" effect on me. Other times I notice an ad it is usually because of its stupidity or offensiveness to me, which makes me remember the product/service and never buy it.
Also as an aside, I cannot remember a time that even a food ad made me buy some food, they just make me more hungry.