Today, in the US, crypto coins are seen as property by the IRS. Therefore, according to policy, if you want today to pay for your coffee with 0.00075 Bitcoins worth about $5 dollars, you also must pay tax on these 0.00075 Bitcoin you just spent.
What tax? Here is a rough way on what this tax is. You have to calculate at what USD/BTC price you purchased these 0.00075 Bitcoins, lets say $250 per Bitcoin. You have to look at what USD price you sold these bitcoins, lets say today at $6600. Then you have to look up your tax rate, lets say 30%. Therefore in addition of paying for your coffee with 0.000075 BTC you also have to write a check to the IRS for 0.00075*(6600–250)*0.30=$1.42
In my eyes volatility is what is preventing crypto currencies from being more used for payments in online commerce.
I believe that crypto currencies are much better adapted than credit cards for online payments (faster, cheaper, non-reversible, simpler, etc). And yet crypto currencies are hardly used at all:
BTC is 300x more volatile than EUR
I strongly believe that lack of adoption is due to the crypto’s volatility. Merchants have costs in fiat currency (USD for example). Having a BTC price for their product that changes by 30% a week is not manageable and provides poor customer experience. Imagine if you wanted to buy a car and the price was today 10 BTC and tomorrow 13 BTC and day after 7 BTC while the normal consumers haggles over $200 for the price of the a $40,000 car and needs hours/days to make the payment. This is not manageable.