Split Marketplace into buy sell and trade

have you aver thought about splitting the forum marketplace into buy sell and trade sections? Im quite interested in selling advertising now, mabie later i will need to buy it and all the time i have to skim thru the bunch of useless threads. Splitting the marketplace forums would be good idea, but if you are against it so why not make some posting rules there lets say thread title must contain [WTB], [WTS] or [WTT] (or whatever you name trate threads) this way members could sort posts by thread titles and find the info they need without skimming thru other posts.