When I started out, I found myself thinking that I must be known by everybody, with all the effort I made. But in reality, I was barely known at all. It feels like you're constantly throwing yourself at everybody, but that's because you're so close to it. The truth is, most people have no idea you exist. It sounds like you may be in a highbrow sort of niche. If that's the case, it's going to take more than ads. Wining over people on reputation and referrals takes lots of time. I would try to get as directly involved as possible. Participate in forums on the subject. Make it be known you're not just an ad floating around.