I do a contest EVERY month for my team. I usually do a contest where they strive to accumulate EA or higher AND recruit a certain amount of people within the month. It keeps them striving towards a goal, makes some friendly competition and helps my team to grow. The best reward for winning? MONEY. Always money. CASH speaks everyone's language. Just make sure everyone has access to PayPal or it can be a hassle getting their reward money to your contest winner.