I bought one of the earlier shows, by just going to the Jewel store that Jess posted the link for. I didn't have to register for an account or anything. I was able to purchase and download through Paypal.
At the shows, at the merch table, they're selling a CD sleeve with the Tunes on Tour logo, signed by Jewel. It's $20 for the sleeve, which has a download code on the back. According to the sleeve that I bought at the Bethlehem Show, the download will expire in 30 days after posting to Tunes on Tour. Allow 7-10 days for posting, most available in 2-3 days. I had to set up an account for this, and the Bethlehem show, is not up yet. Maybe they decided not to post any more shows to the store. Only if you go to the live. I honestly, have no clue. I was surprised to see the sleeves. I'm glad I decided to go into the merch room. Initially, I wasn't going to bother.