Anyhow here is the math I wanted to do:
WU total annual revenue: $5.5 billion
Percent that is remittances to Mexico: 4%
%5,500,000,000 * .04 = $220,000,000
The Great Wall of Trump will cost $10 billion....
Thus, charging a 4.5% fee on every dollar sent from the US to Mexico by one company alone (WU) will generate enough money to pay for the wall in just one year.
Factor in Moneygram and Paypal and the fee could probably drop to around 2%. Built that wall!