BBVA US Customers?

I'm another Charles Schwab fan. I've been using it lately mostly in Jamaica and getting as good a conversion rate as any other method I've seen or been told about. I don't have to worry about which bank's ATM I use or what their fee is, which is especially helpful when I need to make serial withdrawals to get the cash I need. The area we spend most of our time in is fairly remote and there is one ATM within walking distance (which coincidentally is a Scotiabank and charges a fee equivalent to $3.65US); alternatives are a $60 US cab ride away.

What does Schwab get for this service? Perhaps customers that will use their other products which they do make money on. The odd thing is that they require you to have an open "brokerage" (taxable, not IRA or Roth IRA) account, but it doesn't need to have ANY money or investments in it.