I remember that no so long ago, when you were searching for specific item or game - you always got different results. Shops were auto bumping randomly there, mixing all trades. Now if you try that, you will get stable "list" of shops that not changing unless something was bought out.
At first i thought that its popularity working but its not the case. Now i'm almost sure that the later you create your trade, the lower in result it will be. Even when i successfully and manually bumped shop, my new created trade still is last in results.
Bumping works fine for front page, but not for searching... i dont think it's how it suppose to be, but if it is even designed this way - thats not quite fair. (Plus In Chrome, sometimes, not all images loading and require couple refreshes. Just a reminder of another big and very annoying problem. http://i.giphy.com/3EAKxkbxePrcgmYZW0.gif )