But they do not use Visa cards at the same rate as the US. I didn't pull that out of thin air. EU only makes up about 40M of the 200M+ daily transactions VisaNet handles.
"VisaNet authorizes, clears and settles an average of 150 million transactions per day in 200 countries and territories."
Either way, the best way to prove an assertion based on numbers is to source it.