Tips for better merchandising sales:

Have the merchandise booth open when doors open. It's a great place for people who come early to spend time. If you see me standing alone at the booth, stop by and talk to me. Not only will you be wowed by how interesting I am, you'll attract others to come over (and buy your stuff). Announce the location of the merch booth at the end of the show. Come to the booth after the show. Say hi to the fans and sign CDs.