Not many users: The fact is that people, especially the less developed countries like Vietnam, are accustomed to using currencies, gold and silver. They are no more on the same money. Along with many well-known articles on this currency (to be explained later), people are very cautious and have a lot of worries about using bitcoins.
There are only two disadvantages of bitcoin and these disadvantages are since from day one with bitcoin and still these disadvantages are with bitcoin so I think bitcoin must fix these problems because bitcoin is one of the favorite currency and people want to see bitcoin any time any palace first of all bitcoin have no physical shape and secondly bitcoin is only available on internet and you have use it only when you have internet.