My site is going to have specific tags, somewhat like Stack Overflow. I see Trafficspaces has the ability to support contextual ads but there's not a lot of in

My site is going to have specific tags, somewhat like Stack Overflow. I see Trafficspaces has the ability to support contextual ads but there's not a lot of info. Ideally I'd like advertisers to be able to bid on a set of tags--is this possible?