GamePress
Suggestion: Gyms as Pokemon Sellers
Imagine on a Gym is a 3rd button: "Buy or Sell a Pokemon"
If you "Sell a pokemon" you can pick a Price in either Pokecoins or candy (any type you'd get to pick) or dust. That price is then listed next to the pokemon
If you "Buy a pokemon" you agree to the price and it's deducted from your account and sent to the other account.
Now here's my twist, only the team that controls the Pokestop can do this.
If a team is taken over, the seller gets back a fainted pokemon to revive.
My thoughts is this would motivate people to actually stop in (you couldn't see whats there out of range) which would make you want to power it up (or take it down)