Realms Sticky threads:

[Rhubarbtheorc]

you gotta spend money to make money, so my suggestion is to my something like highlighted spots or sticky spots for trade of char or even items. Those who want to get that spot would have to spend some coins or gold or points, w/e. It can be time limited, etc.

[OhieMitzen]

Character sale advertising here on forums is forbidden. So there goes part of your idea.
Item trade is done with trade specific forum sections. From what I've seen, the amount of new trade threads are low. Making a sticky for a cost to quite inactive forum section seems a waste.

Not to mention, bumping the thread is also a thing, though don't be obnoxious about it.

Or are you, by any chance, saying sticky messages to in-game?

[Rhubarbtheorc]

No,no, nothing to do with forum. Nobody reads it anyway. I mean warmane trade page. You have a list of chars there. For example you have 100 ret paladins belf. You can make your arrangment by your parameters, but if someone is to like pay 5 coins, his char would always be in the "premium" section of the trade, making it more visible. So he gets to sell eaiser, warmane gets free coins, and well buyers have to do more search I guess. Or you can like buy description module. I'm just brainstorming here, but you get the idea, its like typical market website.