I wonder though how much of a percentage they take as their fee though...
From
what I can see, it's 1%.
Converting your sales into bitcoin incurs a 1% fee of the amount transferred to the linked Cash App account, and eligibility restrictions may apply. All of your sales that are converted into bitcoin also appear in your Square sales reporting.
For comparison, I looked into the fees that VISA
chargesor other processors charge merchants and saw a complicated structure between Cost per Swiped Retail Transaction, Cost per Online Transaction and Monthly Fee. However, in some cases, it does appear that it could be less than 1%.
One source about it, for example:
https://www.fool.com/money/research/average-credit-card-processing-fees-costs-america/Although here we would have to take into account other aspects such as how long transactions take to be finally settled, for example, which I imagine will be much faster with bitcoin payments.