Just over a month after Verizon announced Share Everything, AT&T is getting into the burgeoning shared data game (as it's been saying it would) with Mobile Share, a tiered set of plans that allow subscribers to split a single bucket of gigabytes across up to ten devices with unlimited messages and voice.

In many ways, the concept is identical to Verizon's — you start with a base price for the data bucket than add a surcharge for each device you attach to it — though the pricing differs somewhat. On AT&T, for instance, a 1GB plan with a single smartphone attached would run $85; on Verizon, the same setup is $90. At 10GB, meanwhile, you'd pay $165 on AT&T and $140 on Verizon, so the best value depends on your particular configuration. Both carriers charge $10 per tablet, $20 per modem / hotspot, and $30 per feature phone, though AT&T has a tiered pricing scheme for smartphones based on the size of the data bucket — at 1GB you pay $45 per smartphone, but that goes down to $30 if you choose the bulky 20GB option. That's twice as large as Verizon's biggest bucket, though both carriers charge $15 per gigabyte in overage, a 50 percent increase from their individual plans.

Att-mobile-share-chart

And individual plans are a key differentiator between the nation's two biggest carriers: the introduction of Mobile Share has no effect on the availability of AT&T's existing offerings, which means new customers won't be forced into a data sharing arrangement if they don't want it. Verizon, meanwhile, has phased out its entire postpaid portfolio outside of Share Everything.

Look for Mobile Share to launch in late August.