Unfortunately freedom and privacy-minded people tend to dislike public displays. But it is a real roadblock we have to overcome. Seeing things in public- hats, bumper stickers, etc. "primes" people to look into it later (even if 10 years later). This is a basic, effective, and universal marketing strategy. Meaning if we don't use it, someone else will. Perhaps there is a way to create a Tor-like onion routing system for advertisements. Guide people down the rabbit hole, but by the time they figure out you are a bitcoiner, you are long gone?