I hope Mark Joyner doesn't mind but this is an extract from an email promoting his book "Mind Control Marketing" and Mark explains the Zeigarnick Effect.
It is a long email so I have edited out sections.
A few years ago I wrote a book on persuasion called "Mind Control Marketing." It became a best seller faster than just any other book I've written ... about 36 hours after its release it was a #1 bestseller.
Want to know one of the most powerful techniques I share in it? It's a technique you can use right away ... and if you use it even half well, it will work like a charm.