I have a great idea for the deals section - which involves a gold stars 1-5 system
+ unauthorised merchant posting
You may have come across this idea when viewing the Argos website, where if someone wants to know how good a product is they look at the reviews and how many gold stars the product gets. This function is used on many forums and is great for just glancing at instead of reading through mountains of posts then deciding. Even with the reviews people sometimes can't make up their mind.
Also - I for one have recently asked on here whether people are more knowledgeable on certain merchants and (before posting a deal) asked for advice quite often. We could also have a general list for all merchants that are not allowed, this in turn will help deal posters who frequently post for unauthorised merchants. This could be added when the user is posting a deal, the unauthorised merchant will pop up and stop anyone posting.
So that's probably 2 things to consider which I personally would improve the site and benefit buyers:
1. Implement a review system namely 1-5 gold stars (half also count)
2. A function when posting a deal warning the user that the merchant they are trying to post for is unauthorised.
Photos of idea are posted below :)