For the last 18 years, Amazon has benefited from the ludicrousness of the US patent system. While the idea of 1-Click online checkouts wasn't new back in the 90s, they were smart enough to patent the concept and enforce their rights as the patent holder.
As a result, anyone using a 1-Click checkout system has been paying them a royalty. That enforcement made barnesandnoble.com change their old 1-Click process to add more steps rather than pay the fee. But that patent expires today.
Depending on who you ask, 1-Click adds as much as $2.4B to Amazon's coffers. That's a nice business on its own right there. But given their revenue was around the $136B mark last year, it's not going to make a massive difference to the company's bottom line.
What it does mean is companies will be free to refine their online checkout processes and systems without worrying that Amazon could come knocking on their door with a cease-and-desist letter or an invoice.
Interestingly, the EU refused to grant a patent to Amazon, on the basis that it was an obvious invention - like patenting the wheel. Canada initially rejected Amazon's application but, after granting it following an appeals process, it amended the guidelines for patent applications.
If you're using a SaaS or applications that licenses 1-Click, I wonder if you'll see a drop in the price, now that the royalty doesn't need to be paid.