People tend to use Linux for mass installs, though. Once you say "it costs $10 to download this software", you have to ask "but what if I want to download it again? Or, conversely, download once but install onto 1000 PCs?"
The fully-correct-and-flexible answer is, sadly, the Microsoft-like enterprisey one: to have a user account and charge the user for a multi-seat license to the software, which provides a product key entered during the installation. That way, you can reuse the same installation image as much as you want, but each activation has a cost.
The fully-correct-and-flexible answer is, sadly, the Microsoft-like enterprisey one: to have a user account and charge the user for a multi-seat license to the software, which provides a product key entered during the installation. That way, you can reuse the same installation image as much as you want, but each activation has a cost.