You pay real money for it. Or you make a board that gets used in the game, that gives you 300 pizzas. Or you make a Mauve Manticore level that gets used in the game, that gives you 500 pizzas. Or you join a guild. The guilds compete against each other in mulitplayer. The winning guilds get some pizzas which the guild leader distribute among the members.
Yes, see here for more information: http://forums.cardhunter.com/threads/pvp-board-contest-constant-submission-thread.7206/
