Two possible approaches are being put into place, both of which charge extra for more usage.
Comcast has been under fire recently, not just for its bandwidth caps, but for the practice of only tracking data use for non-Comcast Xfinity streaming platforms. Comcast denies the cause and effect relationship, but the company's most recent data cap announcement comes right on the heels of a complaint from Netflix CEO Reed Hastings.
Comcast is currently rolling out two different test pricing plans. The first would raise the cap to 300GB and then charge customers $10 for every 50GB they're over. The second would simply create tiers and put customers into those tiers based on usage.
Source: Home Media Magazine