Update: This sale has ended, thanks everyone!
The 2013 Steam Summer Sale starts today, and DisplayFusion Pro on Steam is on sale at a 69% discount ($9.29 USD) until July 22.
For those that aren't familiar with Steam, it's a content platform that sells and manages licenses for games, and more recently, software applications as well. More information about Steam can be found here: http://store.steampowered.com/about/
You can use the Steam license on one or more computers where:
Steam does not need to be running in order to launch DisplayFusion, but the above restrictions are required as per the license agreement, and you'll need to install it through the Steam client.
Feel free to check out DisplayFusion from within the Steam client, or via the Steam Store on the web!