your subscribers will put you on a “swipe file” or “mass email” account. This is usually an account they open with Hotmail and Yahoo – and never bother to read. They simply use it to download free products without having to be bothered by the emails that come later. This means that compelling them through your offer to get them to subscribe will have to be paired with an effort to get them to continue reading.
The place place to compel them is either in the first email or in the actual mini EBook itself. These are the two places in which you are guaranteed to reach them. If you don't reach them hear, you might never get the chance to do so again.
Now, if you're not selling IM products, you wont have to worry about this as much, but you will still want to consider making sure you structure your offer as an incentive for people to subscribe to your list. Many people structure it in a disjointed way that never lines up. People don't understand why they are joining a list in order to download the mini E-Book – and they don't understand what the two have to do with each other.
You will want to make sure you solve this problem by correctly lining up the information in the book with the course that will immediately follow it logically. This will give readers a clear transition.