After my time was done with the Genius Bar folks, I kept my eye on some of the other Genius Bar visitors. Of the five folks I watched, four of them had purchases in hand when they left the store. (I imagine that Apple tracks the revenue generated by Genius Bar visitors, and knows exactly how much money the average Genius Bar visit is worth. It won’t ever happen, but I’d love to see those figures!)
It’s no accident that in newly-renovated stores, most of the smaller items (cases, cables, software) line the walls closest to the Bar at the back of the store.