Based on Black Friday stats..see link below:

“Overall iPad is changing shopping habits, but it has a near monopoly in its form factor at this point. The bigger question is what is causing phone users to behave differently based on the devices they own. The phone market is more mature and has had several years of competition to be able to discern differences in platforms. The pattern is pretty clear with respect to Android: engagement is down as ownership is up. This pattern has not exhibited itself with iPhone, even though it has had a longer time in market.”

http://www.linkedin.com/today/post/article/20121127190246-19021-the-android-engagement-paradox