During casinos' off-seasons, it's common for them to try to lure you in with free play, free food, or a free hotel stay (or all three). As a member, you may get additional offers in mail or online.
Compare the incentives of different casinos or sites, and choose the casino based on the benefits or freebies that are the best for you. These programs will reward you based on how much you play and can give you the opportunity to cash in for additional benefits. Join any 'slot clubs' or 'player perks' your casino offers.