This would only work if there were some rules in place. The only problem is that this would just be a pay to win situation. If everyone starts doing it, then no one would win, because the page would be flooded with people bumping their threads. A better solution is the Google ad method, where a couple more spots at the top are for sale. And people pay for that spot(s) on a daily or weekly basis and have a wait list, but these threads would definitely need quality control. Overall, this is mostly a seller issue, which I'm not, but I feel that if sellers want to pay to advertise then make sure the value matches the payment.