Man, that's a lot of customers in such a short time -- they come and ask because of your Bitcoin sign or you talk to them about it? Because that's some amazing numbers, no other way to describe it, considering you're not advertising digitally for a digital payment method.
Exactly what I thought, 13 costumers in a month is almost 1 costumer paying with cryptocurrency every two days during 30 days.
It leads me to assume OP is from a country which Bitcoin and other cryptos are widely used to ease whatever economical frictions must be going on there.
My country has quite considerable volume in the region (mostly exchanges and stablecoins) and yet I doubt merchants who accept Bitcoin are able to get similar numbers as OP.