The item bag has a limit, so be sure to keep an eye on the inventory before swiping on a PokeStop, lest you waste precious items. Always keep Poke Balls on you. If you’re running out of space, try throwing out some potions or revives if you’re not battling often. You can use Poke Coins to buy more bag space. Poke Coins can be purchased with real-world money, or earned through having a Pokemon defend a Gym.
Originally Posted by: gamespot.com