I got the below email from Xfinity Mobile.
"Updates to your account coming in February
On August 1, we introduced the second generation of the Xfinity Mobile Plan. It includes two additional shared data amounts – 3 GB for $30/mo and 10 GB for $60/mo – as well as HD video resolution for By the Gig lines (and a new Data Saver feature for those who are comfortable with standard video resolution). The additions provide more savings and allow groups and families the flexibility to better build a plan that fits their needs.
To make the shared data amounts available to everyone, we are moving customers on our original plan to the second generation plan. This move will occur on your February billing cycle end date.
A lot is staying the same. Your service won't be disrupted, your billing cycle won't change, and the price for each data option isn't changing at this time:
By the Gig lines stay at $12 for 1 GB, with our two new shared data amounts available
Unlimited is still $45/line per month
All By the Gig lines will default to HD video resolution (720p for smartphones; 1080p for tablets)
You'll still be able to switch between By the Gig and Unlimited at any time – and now you can also change By the Gig data amounts.
Two key differences we want to highlight:
You may experience temporarily slower data when the LTE network is unusually busy.
By the Gig no longer includes an allowance of 100 MB of shared data. In other words, you'll pay a minimum of $12/mo per account for cellular data for your By the Gig lines.
See this comparison chart for details on the two plans.
We'll email again to remind you of this upcoming change. "