There could be a "smart search" option for trades.

How?

I know nothing is certain, principally taking some factors such as the game's bundle tier value or card dropping value may influence otherwise, but using this would be better than "Hi! I'm interested in your games X, Y and Z, would you mind checking my whole list of games that you may already own 90% of them to see if maybe there're someting you don't have? And if you don't have check if you're really interested?". It would filter a lot of unnecessary list browsing to search IF the fellow trader has something you don't, IF these you don't have actually interests you so then you check IF they would be interested in any of your goods. It was awesome to finally have that advanced searching involving "wanted game" and "owned game", but searching it one by one is just matchmaking, still takes as much time (or more) than browsing through the simple search tool.

In case of TL;DR...
It wouldn't makes trades certain, but would significantly increase the chances of trading