dstarr3 :
Fences is a pretty useful piece of software if you have a cluttered desktop. But there's no reason to get it on Steam. You get the same discount if you go directly to their website, get it there.
If someone wants the software, there's not much reason
not to get it on Steam either. Many people would prefer to buy software from a site that they know is more likely to take security seriously, than from some site they've never visited before. And of course, sharing one's billing info with a number of sites is naturally going to be less secure than sharing it with a few, and many people already have accounts with Steam.
From the developer's perspective, they might keep a little more of the profits from a purchase at their own site, but they also need to handle things like payment processing and distribution for the software and its future updates on their own.