This made it super easy and convenient to buy the BitShares 101 book. Just click the "Pay with BitShares client" button, confirm the order in BitShares client, and boom, DRM-free PDF of the book downloaded to my computer. No need to sign up for a new account, no need to give up credit card numbers or my real identity. I love it.
The only improvement I could think of (for digital downloads) is to keep track of the BTS account that paid for the content so that the purchaser could login (using BitShares Login) if they choose to and redownload the digital file without having to repay (in case they lost the file and didn't create a backup).