… got an email from my gym, asking me where I’d been.

It said, in part: “We’ve noticed you haven’t been in as regularly as in recent weeks.”

(In my workout defense, my wife is gone all week so I’ve substituted going to the gym with getting my dog out for exercise every day.)

Pretty impressive. Not only do they need accurate tracking and a rule(s) of thumb defining “regularly,” they need a list of client emails and a mechanism for sending these out.

Whatever communications you plan on sending, an up-to-date email list is the fuel of your marketing engine.