I agree with an earlier reader, maybe Verizon is technically 3G, but I've been a in a lot of areas that my AT&T phone didn't have 3G coverage and the data transfer rate was MUCH faster than the Verizon counter-part.
The ad seems to be pretty clear though. In AT&T's defense, my parents who are nearing 60 would have no idea what the difference between 3G and regular coverage is, and I'm positive my mother would look at those maps and think that Verizon would let her talk to people in more places.
Contrary to an earlier posters comments, people that don't know enough about cell phones to know the difference between 3G and any other type of network are not "extreme idiots". They simply don't care enough to keep up with cell phone technology and so these ads become confusing. I won't go as far to say that Verizon intentionally mislead customers, but that may be what happened regardless.