Usually online merchant which do Digital trade only will use bitcoin , if i am selling cloth i will be taking cash
Why? Once the bitcoin payment has confirmed it can't be reversed. Shouldn't take long to get one confirm.
If you're selling a $10k dress for the Oscars, maybe you want to wait a few more minutes for a couple more confirms.
And another thing is how many people sell $10k Dress lol , what about those small business who sell 10-20 dollar stuff how are they going to use bitcoin for such amount without losing too much when trading back .
These services calculate the amount of BTC the customer needs to pay at checkout then immediately convert it to USD or another fiat currency for the merchant to receive:
The merchant sets up an account on either service and enables the service as a payment gateway on their online store. Customer adds product to their cart and sees their total in Dollars or whatever currency just like normal. Customer then clicks "check out" and is redirected to a Bitpay or Coinbase "pay now" page which computes how much Bitcoin the customer needs to pay using the current exchange value. Customer pays the amount, the BTC is immediately converted back to fiat and the merchant receives the Dollars via direct deposit into their bank just like accepting credit card or PayPal, Dwolla, etc. The merchant could also decide to keep the money in BTC but the choice is up to them.
So the exchange rate problem has been solved on the merchant side at least.