In the beginning, BTC could be used to exchange of low value of virtual items, such as buying web sites or game points, virtual items, etc., afterwards, some people in order to get these virtual items, items may be in online auction own reality for BTC, others want to buy the real goods, but no BTC at hand, and then use real money to exchange BTC, as a result, BTC begin to flow, and have a "value".
In other words, bitcoin is inherently valuable as a means of payment; If it loses its function as a means of payment, it becomes worthless.
The value of money: it exists because of payment.
I do not think that bitcoi is now a currency, I consider it an asset that can be compared to gold or silver. I think, because of its weak payment capacity per minute, the price for processing the payment and much more. I would bet on bitcoin cash, which can become the first currency of bitcoin.