If you ad something to the thread later, like a new pic or info, it will get moved up in the overall thread page. If it's a decent item at a decent price it will sell, plenty of people go back and look several pages deep. Also, you can sort for "for sale" items only too.
Worst case you can close and delete the ad and maybe listed it again later, with perhaps a different price. That is a big factor in sales...next to LPU versus shipping, payment options, and feedback too. If you sold somewhere else and have feedback, might want to link to it as a reference. Take good pics of your item, and describe it well.
Did I mention price too?
Good luck on your sale...this is a GREAT place to do business as a seller and buyer.