I wouldn't give up so quickly

What you're doing has been tried in the past with varying degrees of success. Usually I would see some real GCC activity but this would tend to wane after 1-2 months. You would probably need to keep posting on the board periodically and really stay in GCC for half a day or something to get it to work. The real difficulty is that GCC has simply been much less active for the past few years as compared with how it used to be - there are simply less active visitors on the site. If things can be improved that may change in 6 months or a year.