You've just finished a node.js site. It's a folder with some files and a my_main_file.js which handles the requests. The thing works on your machine by running node my_main_file.js. How do you deliver this solution to a client, though? Are you supposed to say 'take this folder, install node.js, run that command line and your site will be online'?
The answer is yes. This is quite a bit less complicated than delivering a servable site on other platforms. There are nodejs installation binaries for just about every platform and then it's as simple as:
$ node site/my_main_file
Or maybe there's one more step to install dependencies. Either way, it's about as simple as it gets.