There's a bit of overlap between the three as well. I'd say that it's for investment use but I also have the curiosity to dig out the facts and figure out what lies beneath it. I'm not so sure that many people are in it for strictly that reason, because if they wanted to research and learn about the coin, chances are they'd probably want to invest in it too.

What about transfer of money? Some use it as a method to send money from one place to another without having to pay large amounts of tax in the receiving country.