You can't throw a dead Blackberry phone at a pundit without hearing somebody talk about how customers are moving to mobile.
Many folks count the iPad as a mobile device. This is an arbitrary designation, one often made to make mobile look better than it really is.
If you want to see if the iPad is really part of the mobile revolution, take a look at where purchases happen. Segment customers who buy traditionally via your e-commerce site, customers who buy via a tablet, and customers who buy via a smartphone. Once customers are segmented, look at the channel used in the very next purchase.
If an iPad customer shops via the iPad on the very next purchase, then you have a customer base making the transition to new devices. If the iPad customer switches back to old-school e-commerce shopping, then you've got experimentation happening, you don't have a customer base that buys into new technology just yet.
We saw this with e-commerce in the late 1990s ... customers ordered online, then went back to buying via the telephone. By the early 2000s, customers ordered online and stayed online ... at that point, the mass exodus from the call center was underway.
Simply repeat the work you did a decade a go, this time measuring the shift from traditional e-commerce to tablets/mobile.