So i thing having a bitcoin shop in big city would be perfect because many people will then come to know about bitcoin.
Exactly, basically the best place to advertise was on the higher population that is what an advertiser always aims right. Same thing with bitcoin best way of promoting it is to let people experience it and the best place to do it is obviously in the place were most of the population were at.
What you said is perfect we the users of bitcoin if we are in any business then we should start to promote bitcoin for payment and tell our friends and customers about bitcoin and about its payment option to buy your products then the customer will try to find the details about bitcoin as you will also give discount on bitcoin purchase so like this the bitcoin awareness will be created and it will be good advertisement for bitcoin