More people would use desktop apps if they were easier to install. I tried to talk my mom through installing skype the other day, and we hit a snag. So she just used the video chat in gmail. Skype would have been better for her for various reasons, but she settled. If Skype were in an app store, she'd have bought it.

I install way more software when I'm in a linux environment, since it's just one simple command to do so.