The reason it is a function that calls itself is to not pollute the global namespace. The rewritten expanded example leaks "gaScript" to the global namespace wh

The reason it is a function that calls itself is to not pollute the global namespace. The rewritten expanded example leaks "gaScript" to the global namespace which is a little rude if you are injecting your script onto a third-party page and using a random or long function name is not as clean a solution since it still leaves dirt and takes more bytes.