[Retric]

real estate pays a dividend in the form of use of that land.

If I own a house I get to use the house today and still have a house tomorrow. With a field I could grow crops and then still have a field next year.

Commodities are an interesting 3rd thing. But, closer to buying something from a wholesaler than an investment as they represent actual goods (ie Oil) that will be sent somewhere. Think of it like this, if you buy coffee contract you get coffee which can be sold off. However it's a physical thing and it's got a physical expiration date, if you keep it in a pile somewhere for 10 years you end up with dirt.

[darawk]

Bitcoin provides a service though - a service that has demonstrable economic utility. Specifically: international value transfer. There are existing mechanisms for this (western union, swift) and they have costs. The sum of those costs is a reasonable way to think about Bitcoin's theoretical value by substitution, because it costs bitcoin to move bitcoin. And therefore if Bitcoin were to replace all other intl. value transfer mechanisms, the sum of those two sets of costs should be comparable.

[Retric]

Owning bitcoins don't facilitate these transactions by third party's. The service can create value but don't let the name of the service be confused with the coins.

You could speculate that the utility created will increase the value of the coins you hold. However, unlike mining there is no connection between buying a coin and enabling other people to do these transactions.