Have you ever purchased software that required installment on your server... but you never did it... because you didn't know how?
Or have you ever wanted to purchase software like this, but didn't because you were already fully aware of your technical deficiencies?
I know this has happened to me.
Yesterday, I was researching split-testing software. I looked at a lot of different software products. None of them offer an "installed" option.
Now, I have in the past purchased two separate pieces of software that offered installment, for an additional fee, on the back-end. But this was not advertised on the front-end.
I believe anybody selling software that requires installment on a server could sell more by offering an "installed" price. In other words, $29 for the software or $49 for the software installed. It would require a little more work on the part of the developer/reseller... but I bet it'd be worth it.