While many new and current Apple iPhone users have been looking forward to drop-free calls using Verizon's CDMA pipelines, there is the matter of simultaneous voice and data. Unless hooked up to Wi-Fi, Verizon customers cannot have the pleasure of making a call and accessing data at the same time. It is just one of those things about CDMA networks that makes them different from GSM.
So if you're AT&T and worried about losing some customers, why not highlight this difference in a commercial that shows the dire consequences of not being able to use voice and data together?
source: Redmond Pie (1), (2)