The "freefile" version offered through the IRS partnership cannot, by law, be advertised. The other companies that offer it don't advertise either, right?
The free product is indeed free for many users with upgrades for plenty of others an option or in some cases a requirement.
Also, you know, TurboTax is a company not a charity so why would they pay money (for ads) to attract people to use a service on which they make none?
