If all countries can accepted crypto currencies in there various countries, as a means of payment and as a means of online exchanges, such as money is, money is anything use as a means of exchange and general acceptable. With the means I think all cryptocurrencies (bitcoin) will definitely go round the world, and will be use as a means of exchange. I will be so grateful to the creation of crypto currencies. This will also help our future generation, Remember something when we do international transfer across the countries, it may take a while to get the money to your local bank account, but with cryptocurrency you can get instant reflection if bitcoin etc is transfer to wallet,And you can make use of your coin (bitcoin ETC).
FYI You might be interested in the responses to this recent thread since 'mainstream' and acceptance are closely related -->
Poll: when will cryptocurrency go mainstream? I have been pondering this question recently. While bitcoin is decentralized and not dependent on governments for its existence I believe that it is dependent on countries for its acceptance (or at least the degree of acceptance). Countries support for bitcoin varies considerably from where ownership and trade is practically illegal to more 'bitcoin friendly' countries. All governments have a fiat currency which drives its economy and bitcoin doesn't do it any favors so it is understandable that even so-called 'bitcoin friendly' countries are really just 'bitcoin tolerant'. The larger bitcoin gets the great the perceived threat to their fiat currency the more likely the country will become less tolerant. Your example of international transfers is a great one where bitcoin can do a much better job than traditional means however that isn't going to drive wide spread acceptance IMHO. It needs more use cases where it is a superior the alternatives.
Take the USA which I would describe as bitcoin tolerant...Yes, I can own and trade bitcoins BUT I needed to track
every exchange and report it on my taxes. That means if I was to use bitcoins to buy, say, my dinner I would have to track this micro purchase and report it as a gain (or loss) which to me is a massive barrier toward its usage. Hence it largely is viewed/used as commodity or a 'store of value' for speculative investment. In this space most countries can tolerate bitcoin because it doesn't go head to head with their own fiat currency. They just need to regulate it so they can get their proper tax cut out of any investment appreciation and they are happy.
Satoshi's response to 'Bitcoins are most like shares of common stock' thread:Bitcoins have no dividend or potential future dividend, therefore not like a stock.
More like a collectible or commodity.
The problem is that the alternative for micro purchases to the vast majority (of people living in the USA at least) is a touch act to follow even if you ignore the tax tracking issue. Credit cards are widely accepted, easy to use, and even pays me money back to use it (yes I am blessed in that I can pay off all my CC debt). Sure, they are susceptible to fraud but largely I am not held liable when it occurs unless I am grossly negligent. Can bitcoin really compete with that use case?
Satoshi outlines an interesting 'fringe' use case that unfortunately won't lead to universal acceptance, but is interesting Bitcoin would be convenient for people who don't have a credit card or don't want to use the cards they have, either don't want the spouse to see it on the bill or don't trust giving their number to "porn guys", or afraid of recurring billing.