As you can see in the charts below, there is a spike in visitors per store that begins in Q1 2010. Dediu looks at several possibilities for the spike including store redesigns to allow for more traffic, additional store openings, and staffing changes. He concludes that the most likely cause isn't one of those factors but instead the launch of the iPad in April 2010.
The iPad is something that needs to be discovered with a retail experience. You can sense this when you visit the stores and the placement of the iPads within. It all points to a something more profound: that the stores are brand ambassadors. Apple products create a purchase decision by speaking directly to the users. For the type of product Apple makes, that conversation can only happen face-to-face. The place where this meeting happens is the store.
Take a look at the charts below for more info...