DJ Khaled is a glorified agent. His contributions on the songs he's featured in is having the number of the actual artists (which let's be honest, a lot of them are industry plants to begin with) and convincing them to do a song with someone else. Notice how he is never in a feat with 1 other guy, it's always at least him and 2 other people.
The one thing he did differently was that isntead of just taking a payment for placing 5 calls total, he says "dj Khaled" once, gets on the artist list and gets royalties on that song.