I have to disagree. Its not great as treating it as a commodity (with capital gains taxes for example) will mean that it wont become a dominant medium of exchange.
Now for transfers it is not cheap if you take into account the spread! So where exactly is the value??? I dont see it.
It may not be dominant but it will still be a medium. I think BTC won't replace fiat completely but it will continue to exist.
Let's say you are a freelancer, a constructor, writer, artist - btc will allow you to get paid for your services without registering a business. Your private details won't be sold by a bank to some advert agency, they won't monitor your income, won't track your investments like they already do. Currently the government knows where you work, buy your food, how much you earn, your credit rates. With btc you are the captain of your own ship. I know people who took credit in foreign currency and it suddenly went up, so now they are completely screwed as the interest rates take 60% of their income. There are still people in this world who want to be independent. I would love to be able to just trade with people, like in the old days - you had a silver or gold coin and you could exchange it for some goods or services without big brother watching from above.
Any larger business is well known by local government. Having customers is a public act (now it depends on the number obviously, but any medium sized business is well know in the area). They will knock on your door and say: We know you have sold product and services. Your local bank account doesnt show transactions in our government currencies. Care to explain? What? You are using cryptocurrencies. Well we will put you in prison for life or execute you. See how easy it is? Again transactions are the tax base (thats why bank accounts are not anonymous, they want to calculate your profit!).
Now nobody will be safe from these controls. What you have a car? How did you earn money for that car? Cant show it in your transactions with your bank in local currencies? Death penality! See how that works? They go after the small guy as well, so nobody is safe. And you assumed bitcoin is 100% anonymous which it is not (remember all the personal details you gave the exchange).
So I dont see anybody using bitcoin as a medium of exchange in a significant way because they would have to pay taxes on every transaction. Then anonymity is lost. If you dont pay taxes you end up in jail.
Firstly, you can sell in the internet just like they do with miners or anything else these days. Secondly do you really think they will put half of the population in prison or as you say execute? In the EU they wanted to enforce ACTA last year and people didn't allow it. People have the power to change what they don't like.