A direct marketing strategy that involves sending out a number of promotional pieces over a period of time to a subset of sales leads.
"In Cycle 1, sales-ready leads are forwarded to the appropriate sales person. Prospects who have shown some level of interest but are not sales-ready, are retained for incubation through Cycles 2 and 3. The balance of sales leads with no current value (up to 50 percent or more of the total) are temporarily disqualified and put into automatic drip marketing channels, which support a steady flow of attention and information to prospects."
Christopher Ryan, "One-to-One Marketing: Panacea or Pipe-Dream for Business Marketers?," Direct Marketing, October 1, 1999
The phrase "drip marketing" may sound as though it's based on the practice of water torture, but it actually comes from the phrase "drip irrigation." This is an agriculture/gardening technique in which small amounts of water are fed to plants over long periods of time.
Unfortunately for anyone who is the target of a drip marketing campaign, many marketers believe in something called the "Law of 29," which states that on average a "prospect" won't turn into a "client" until they've seen your marketing message at least 29 times (insert groan of dismay here).