They have consumption data and they know what people say they are willing to spend on internet, and they know what the demand usage is likely to be in the future.
They can do the arithmetic!
This "experiment" is solely to "See what the market will bear" or rather to seehow much they can get away with gougeing the public!
That's exactly right. They have the data right in front of them. The reason they won't share it with anyone, or release raw data of any kind, should tell a smart consumer volumes.
As for the TWC trials, the "experiment" was about framing public relations and marketing to make the change seem necessary...they'd already perfected the back office structure in Beaumont months earlier.