Verizon-AT&T ad war: Adding insult to injury

For all of the disparaging remarks that Verizon Wireless and AT&T have made about each other in TV spots this holiday season, the advertising war has buoyed brand awareness for both carriers. The No. 1 and No. 2 carriers trade attacks, the implication is that there are only a couple of serious alternatives in the mobile market. Sprint and T-Mobile USA aren't even on the radar.