Now try to get AT&T to tell you the difference between the 2010 grandfathered iPad unlimited data plan sold direct from the iPad UI, currently hovering around $30/month ... any any of the above, or in particular the business iPad add-on claiming to offer unlimited iPad data for $20/month.

// This was the plan that was only around for a few months at launch:

https://www.macrumors.com/2010/06/02/atandt-replaces-ipad-un...

// And then sort of reintroduced in 2017, pulled in 2020:

https://www.rvmobileinternet.com/gear/att-dataconnect-tablet...