Merchants will start accepting bitcoins as a mode of payment only if the people around them are aware about bitcoins and are willing to pay in bitcoins and if none is aware about bitcoin then there is no point in accepting bitcoins as a payment method.
Merchants will accept bitcoin if it's profitable for them, they don't care about people awareness or whatever, it's simple and all is about profit, it's fact
I think the seller is not only thinking about profit dude, they also think how to maintain a good service so that customers come again. So a shop must know how bitcoin conditions in their area. When it is in the area surrounding many use bitcoin, and bitcoin as a payment they receive. So it is one of the services that benefit the customers I guess. Thank you