What are the pros and cons of this ? Can this increase sales in the physical store because some would like to spend crypto in bulk which they are getting from some source ?
Fiat is still highly regarded and using Fiat right now as a means of payment is still effective and people have no complains doing so as their sales has still been ok.
Although I will say if you run a physical store and still operate online and you have customers with from different countries then the use of Crypto-currency can increase your sales as transaction made with crypto are more easier, faster and considerably cheaper.
Bitcoin doesn't stop fiat to be used for steady transactions same way Fiat does not stop bitcoin either. Both can be use to carry out business, sealing deals as long as the parties involved are cool with it.
Apart from owning an online store, local stores can make use of Bitcoin if the customers coming there are people who are willing to pay with Bitcoin. I have visited a super store that accepts bitcoin as payment personally.