When I am the seller/poster, I actually prefer to trade. It is more fun for me, but sometimes I sell to recoup funds for another purchase. Also, just because someone puts a FT only in their ad doesn't mean they won't sell. For example, this is always the case with me if and when I post something FT only. If it is FT, it is FS.
On the flip side, as a potential buyer, I always prefer the item I am looking at to be FS/FT.
On the flip side, as a potential buyer, I always prefer the item I am looking at to be FS/FT.