That's correct, licensed dealers are required to implement a background check. Jimmy-bob-bobby-jimmy that has a booth at the same show that is selling some of his arsenal doesn't have to ask any questions or require a background check to whom buys his firearms. Just the same as those that buy from a classified ad or other private sale.
If Jimmy Bob wants to sell his guns outside the gun show there is no requirement for a background check either. That means him doing so at the gun show is not a loophole.
Game, set, match.
That's the point. If Jimmy-bobby wants to sell his guns at the show or on a classified ad, the laws are the same, no background check required.
Check mate.
No check mate, you were intellectually fried. Private sales between citizens has never been a problem requiring correction, and has absolutely no real bearing on the illegal gun market.
What most of you mental midgets fail to understand is that guns are not the problem. People are the problem, and that is where the answer lies. Few, if any, of the mass killers that have made the news lately, would have had any difficulty passing a background check.