What are the benefits to the US Electoral College system?

So I'm a New Zealander and I have a pretty good idea on how the electoral college system works but it honestly sounds like something that can be easily corrupted and it feels like it renders the popular vote absolutely useless unless I'm totally missing something obvious?

So yeah if someone could explain to me what the benefits of such a system are, that would be awesome.

Edit - Thanks for the replies so far, already learning a lot!