How feasible is it that I can sell a line on my family plan that has unlimited data? Will the owner transfer kill the data plan? I have 3 lines with unlimited data that are now going to go to waste due to my family members streamlining their budgets or leaving the country. However, I am still staying so, with 3 lines, I would like to earn a profit on the value of the data plan. This is on AT&T by the way.