Minimizing customer turnover depends, in large part, on making sure your customers know they’re customers — that they self-identify as customers of yours. One wildly under-utilized tool in this regard is the humble t-shirt. Come up with something light-hearted that speaks to your customer, invest in great design, then figure out a fun way to distribute them. Customers feel recognized. Then they wear your message out and about — to the game, the store, the gym — effectively letting the whole wide world know they’re your customers. Which makes other people think about being your customers.