The great majority of ISPs provide some CGI service, and more and more run systems that are compatible with MiniVend. The catalog configurator for MiniVend is designed to figure out many ISP directory setups.
Almost any Internet Service Provider (ISP) system should be able to run MiniVend, but some cannot (or will not) run MiniVend at all. On top of that, many times ISP personnel are too busy to help, won't help, or don't know enough to help. Some are secretive about details of the setup of their systems.
MiniVend does require a stable platform underneath it. Many ISP servers are heavily loaded (especially low-cost ones). If you run on a server which is constantly running out of memory and file descriptors, you will not be happy with your results with MiniVend.
Virtual servers that don't provide shell access are not really usable for MiniVend without direct support from the ISP -- unless you are a CGI/Perl wizard who can figure out how to do it. 8-) It can be done (with a good deal of difficulty) on some virtual servers.
Iserver.com and others who use an chroot HTTP daemon for each user will require some source-code twiddling to get the paths for vlink right -- the catalog configurator will not do the trick. See the mail list archives for the hack.
MiniVend does require a lot of memory, and it does run as a daemon. You will find that that vexes a fair number of ISPs. I have found it difficult to provide power and speed without using memory, so it will have to stay that way for the time being.
All in all, you can have a fair amount of confidence that your ISP can run MiniVend. Or, you can get one who will. 8-)