In this episode of SmartWatch, we take a look at the rise and possible fall of the tablet. As net phone additions lagged in the second quarter, the major carriers leaned on tablet additions to prop up their numbers. Big Red added 1.4 million postpaid subscribers, reporting that it had added 304,000 postpaid phone net additions and whopping 1.15 million postpaid tablets. AT&T couldn’t touch Verizon tablet additions, but it too supplemented with slates. AT&T saw 700,000 postpaid smartphone net adds and 366,000 postpaid tablet net adds.Even Sprint’s prepaid handset losses were offset by 535,000 net prepaid tablet adds. Still, analysts are cautious about what to expect going forward, with some saying the tablet’s role as a growth driver could be fleeting.