Lindsey gives business owners a free written second opinion on their card processing statement. If their current setup is fine, he tells them to stay put. This page writes a short intro email you send from your own inbox.
Copy Lindsey on the email so he can reply to you both. "Open in my email" may not work on every device; copying always does.
Lindsey replies to you both, sets up a short call, and asks for one recent processing statement. The review is free and comes back in writing. There's no pressure to switch, and the person you introduced decides what to do with it.