@TheOneMCMK: Not sold per se. They made an agreement. Spider-man could be part of the MCU but Sony had to give up merch rights. After the flop of Amazing Spider-man 2, Sony was desperrate to get the movies back on track. Well...it worked. MCU spidey movies made a fortune.
So, I see Spider-man will be exclusive and free to sony consoles for the Avengers game. Not surprised honestly. They own the game and movie rights to the character . Sucks for users on the other platforms though.