"Co-op is there to be used," said Cammie Mannino, owner of Halfway Down the Stairs in Rochester, Mich. "One of the tricks is that you end up with $110 here and $68 there. You go to use that in an ad, and it costs you $400." Now when she has co-op money left after promoting author events with print or radio advertising and/or newsletter listings, she sets up an in-store display. "It's so simple," Mannino said. "Basically I take a photo and I send it with an invoice for $50 per book." She's also started using special display co-op that many publishers offer above and beyond her store's regular co-op pool. Mannino advises booksellers to "get over their aversion to co-op. This spring I put up displays of A Good Day's Fishing by James Prosek and If I Were a Lion by Sarah Weeks, and I invoiced Simon & Schuster."