Too often I come across health pros that avoid email like the plague. However, those that partake are always doing it in some funky form that is less than desirable. Online marketers make most of their money from email marketing, and I found a bunch of mistakes they avoid when they are running their campaigns.
You can learn from their costly mistakes, and avoid losing any money with your own campaigns. Check out the article by Andrew King: Oops! How to Deal With Common Email Marketing Mistakes.