I really do think that a StumbleUpon for ads would be great. People willingly tell SU what they like and don't like (which is what Facebook and Google are doing, but without explicit, up-front, opt-in consent). SU has millions of users, including me.
By telling them what content I want to see and what I don't want to see, I'm pretty happy knowing that I'm seeing exactly what I told them I wanted to see. Advertisers could do a lot in this space, and it sounds exactly like what you described.
By telling them what content I want to see and what I don't want to see, I'm pretty happy knowing that I'm seeing exactly what I told them I wanted to see. Advertisers could do a lot in this space, and it sounds exactly like what you described.