Most of my business flows from folks that visit our website and register there and most are from up north, thinking about relocating to Florida. My contact is the telephone and email. I dont meet them untill they actually get on the plane and head on down.....So I DRIP on them. regular phone calls and email just to say hello and to get as much info as I can regarding their needs. I enter a search into the mls once and then every time a new listing comes onto the market that meets their criteria they get an email (and so do I) with the info. It also creates a website where they can save or reject listings and leave comments.  Ive worked this way with clients for over a year before they visit.  nearly all my business (such as it is) is generated this way (19 closed transactions this year

This is probably not the kind of drip campaign you are talking about but its what I do to stay in contact with folks that I think will buy sometime in the future