New e-commerce site Cointagion is offering e-books for bitcoins -- and lets users buy books without even touching their computers.

Selling books for bitcoins isn't particularly significant. Online merchants who accept the digital currency -- and there are more of them every day -- already offer everything from consumer electronics to porn to coffee and cupcakes.

But where Cointagion is innovating is in the payment mechanism. While Amazon offers a one-click checkout process for buying books on its site, which makes Kindle purchases easy, what Cointagion offers is a "no-touch" solution.

Instead of asking customers to go through a multi-stage, form-filling process and pay in bitcoins at the end, Cointagion can generate custom addresses in real time, containing information about both the user and the product.

Cointagion’s founder, Chicago-based medical software programmer Conrad Barski, published a white paper (PDF) on the website explaining his approach to quick bitcoin payment processing, with minimal steps for e-commerce sites. He does it using QR codes.

Using QR codes to display bitcoin addresses is routine these days. Search engine WolframAlpha, for example, will automatically generate them for you. But Barski has adapted this to dynamic address generation for different products on a website.

He uses session information from the user's browser -- identifying information about the product-- and a dynamically generated bitcoin address, in what he calls a "triple". E-commerce sites can pre-generate triples for the user when they load a webpage, and represent them as product-specific QR codes alongside each product listed on the webpage. In that way, when you want to buy a product, you can simply scan the code with your mobile wallet.

It's simple, but could be significant for e-commerce companies that want to explore bitcoin. According to the Baymard Institute, an average of two out of every three shopping cart sessions are abandoned before an online customer completes a transaction.

Others offering downloadable media also offer relatively simple payment processes. For example, Steambits, which offers games for download in exchange for bitcoins, requires an email address, to which it sends game codes and download instructions. It then displays an alphanumeric bitcoin address to be pasted into a bitcoin wallet. It's relatively simple, but not as simple as Cointagion's approach.

While Cointagion’s choices are relatively limited at present, and are weighted toward technical books, the product quality is high. It has partnered with No Starch Press, a specialist publisher of technical books that is also distributed by publishing giant O'Reilly Media in the US.

What's more, Barski’s no-touch principle could be used anywhere. It will be most effective for digital goods that can be instantly downloaded. Anyone buying physical goods will still need to set up an account with a delivery address ... although after that's been done once, no-touch purchases would be possible.