I Have An Idea??

No - the ad would still be live, it would just prevent him from starting another ad
I'm confused?? I wasn't talking about his/her "ad". I was talking about the PM feature. If the first buyer writes a PM to the seller and the seller's box only has one slot for that one PM (from the buyer) then the seller will get a message (alerting him/her that there's a message). Once the seller tries to respond he won't be able to because his PM box is full?? He/she would be forced to clear his/her box to continue communicating. Isn't that how it would work??

treblig