Comcast will be trying at least two different approaches in test markets. While the company used the term "at least," the company only listed two test scenarios. The first new approach will start with a 300GB allotment for Comcast's Internet Essentials, Economy, and Performance "Performance" Tiers. There would be increased allotments of data for successive tiers of higher-speed data service (e.g., Blast and Extreme). Those at a specific performance tier that need a higher data allotment but don't want to move to another performance tier can buy additional data (e.g., $10 for 50GB).
The second scenario would raise the 250GB allotment for all packages to 300GB and then offer additional data beyond that at an added cost. Once again, the suggested amount would be $10 for 50GB.
The real winners, at least during the test phase, are those outside the test markets. That is because Comcast will suspend the data cap completely in those areas. Want to run BitTorrent 24x7? Here's your chance (all copyright issues aside).
Comcast did say it would notify customers, so Comcast customers, watch your email inbox for notifications, perhaps coming soon.