To be honest Bitcoin value is not stable yet I don't see the point of using it, some Bitcoin enthusiasts use them though.
To use bitcoin you need not to worry about the stable value of bitcoin, but only for holding purpose. You may make use of the price of bitcoin which is currently more fluctuating. Yes, when you turn as investor you will love fluctuations for sure.
Yes untill and unless you are investor dont worry about it...if your are the person who is looking for the decent pay then just join to the singed campain and spend much time there and earn as much as possible.....regarding to the question raised for why customers should go for btc...it is easy to use and more profitable then other coins....