Does bitcoin value will increase in the future if more people decide to use it?
Yes it is, the more users the higher it's price to be. And it's nearly possible to happen because of its continuously growing population of users which is a good factor of a constant increasing of its market value.
The increasing number of bitcoin users will continue for a long long time, because still bitcoin is becoming more popular and new people are entering in bitcoin world, therefore bitcoin demand is also increase and to the price is. I think that bitcoin price will continue increasing and very soon its price will even reach to 100000$ in next few years. Therefore we should try to buy bitcoin in current cheap price and get good profit when its price reach to such a high value.