Remind Your Patrons: Take A Good Idea From DropBox

Aaron Schmidt: Here’s what Dropbox sends when someone who signed up for the service hasn’t recently used it. These go out only occasionally (from what I understand, I don’t think I’ve ever not used it since signing up!) so it isn’t overbearing or terribly spammy. Plus? It is short, easy to read and rather engaging.
Are any libraries sending out email prompts like this when someone hasn’t used their library card?