Tom is an AT&T customer, and currently has a data plan that includes rollover data. Normally, he and the other person on his plan are very precise: he says that they normally use 2.8 GB of their shared 3 GB plan. Recently, their normal practices didn’t work, and they had to dip into the rollover data. That’s when they learned that rollover data is only useful if your data use fluctuates wildly from month to month. [More]
