WhatsGaming is a FIFA coins seller website and it has an automatic system. No other website has this. The automatic system works in Player Auction method this way: The gamers will pay, they will go to their account in WhatsGaming, the system will give them a player pack automatically (based on how much FUT Coins they have bought and some other criteria) and then the gamer will add those players to the transfer market. The system will automatically find the players and buy them from the gamer. And easy like that the FUT Coins will be added to the gamer's account.
But what is the difference between WhatsGaming and other sites?
Other websites do this manually. And the gamer must call them via chat that he has placed the players on the transfer market. And some times the website admins buy the wrong players and the FIFA Coins will go to the wrong account. Such mistakes never happen in WhatsGaming because the Player Auction platform is automated.