Aside from tilly's points, I've also found that some of my clients with the cheaper/more-restrictive web hosting plans are only allowed ftp access to the server, not ssh (or other shell) access. If your Perl uses any modules that aren't already provided by the hosting service, they're a little trickier to install with only ftp and can be impossible to install in some cases (e.g., xs-based modules when you don't have access to a build environment compatible with the target web host).