AT&T has announced that starting Friday, it will offer $100 off any cellular-enabled iPad or Android tablet purchase in exchange for committing to a 2-year data plan contract. You can still pay full price and stick with standard month-to-month data plans, but if you know you'll use cellular data regularly, you can save almost the full price of the extra LTE and GPS hardware in the iPad "Wi-Fi + Cellular" models.

This appears to be the first time that a carrier has offered what amounts to a device subsidy for a tablet, though the practice has been commonplace for cellphones for years. But the subsidy is still less than what's typically applied smartphones, which tend to be in the range of $200-400.

AT&T Chief Marketing Officer David Christopher noted that AT&T has one of the largest variety of tablets available on its network. "We're giving our customers even more reason to stock up on the hottest device of the season, and just in time for the holidays," he said in a statement.

Customers can still add their tablet to an existing "Mobile Share" data plan for $10 per month, and use the same bucket of gigabytes of data as a smartphone, laptop, or other combination of devices. Or they can use one of the existing month-to-month "Data Connect" plans specific to their iPad or other tablet.

A $100 savings is nothing to sneeze at, but is it worth committing to AT&T for two full years?