I always build my websites with the long term user community in mind, the goal is to retain users and get them active in my site, however I find that ad networks like Adwords are the best way to drive a lot of traffic to my site. I am interested in soon applying for the more exclusive ad networks, like Tribal Fusion and am wondering if they check up on whether your impressions are coming from a program like Adwords, if these will count towards your total impressions and unique visitor count.
What's different between Adwords users and uses you get from Google's main search engine. Not much different really as they are all real traffic where you are getting them legitally and not using TOS breakers like automated trarffic, robot traffic, etc.