Thanks for the feedback cmer! And you're totally right—we want to be very careful about using the word free. We are really a "pay what you want" service.
We initially offered returns for a flat $10, but being new in this space, we found it was difficult to get attention and that many were still doing their taxes on paper because of the perception that they had to pay. We're hoping we can convince many of these paper filers to switch knowing that payment is optional, not mandatory.