Customers will only use bitcoins in paying your service or buying your goods when they are already using it. When they are paying you in the cashier and you introduced bitcoin to them, of course they will not grab their phone and do research about it. They would simply say 'no' to you and then carry on to their day. If you're lucky and that customer happened to have a lot of spare time, then maybe the next time he comes to your shop, he already knows about bitcoin and use it as a payment.
Bitcoin can be used for many different ways,and which is best suited for a particular individual he can use it for that.While if some one wants to send money online over the world with so less fees then he can use it for that,or being anonymous or wants to gamble online bitcoin can be used .