Opt in email marketing can be a great way to invite repeat visitors to your site and if you are an authority in your niche, it can also be a great way to generate income by selling to your list. Instructors and mentors who teach this methodology commonly state that the money is in the list. Unfortunately, for many beginners, building a list is much easier than using it to generate income. When broadcasting to or blasting a list, there will always be individuals who unsubscribe. The trick is to retain...