A News Letter will always work for an interested prospect. Just consider the News Letters you are interested in. What News Letters do you always open. I open a news Letter because I know that I will get information that will help me with the subject of that News Letter.
One way to keep your subscribers interested is to tell stories.
I kept subscribers interested in a News Letter that I published by telling them I was going to set a goal for myself.
I told them that I was going to set a goal for myself of making $100.00 per day, starting from scratch with a budget of only $500.00
I told them that I would tell them every thing that I did to reach my goal in my weekly News Letter.
This way I would keep them interested enough to see if I would reach my goal. This way I had a better chance of them opening my News Letter
Then after 52 weeks I have a product that I offer as a free gift to any one who visits my web site.