This article is not a duplicate of the E-mail drip marketing article. I wrote this article for the exact reason that email drip marketing alone is too narrow of a view on this subject matter. Drip Marketing is a practice unto itself, not dependent upon the medium of email alone. If you look at the article's content, I gave 3 examples of mediums in which drip marketing can be done and cited the E-mail drip marketing article as one of them.
If anything, the E-mail drip marketing article needs to be absorbed into this, or redirected here.
A reference that I added was removed because Mr. Ollie believed it represented a conflict of interest. I don't see it that way as it is a neutral article. Nevertheless, the Wikipedia policy he links to implies that anyone who specializes in a topic may have a conflict of interest--and under that definition this may represent a conflict of interest.
The Wikipedia help on the policy page recommends moving the reference to the talk page so I am adding it below. Please let me know if I should change the example to make it more neutral. Thank you. 
- bbmarketingplus.com/blog/2010/09/08/drip-campaigns-keep-your-company-top-of-mind-5-steps-for-success-an-example/ Drip campaigns keep your company top of mind: 5 steps for success + an example