Why would I want to create an account and then manually enter in my favourite artists?

Because you're not using iTunes. I don't. I agree it's not the best experience ever, but it's a great solution for people like me using small music players (Pragha) that will never be supported by services like this.

It seems to let you load artists from your last.fm and facebook profile, as well as manual entry.

Cool - thanks for the link!