You already know that they are interested in solving a problem, which you can help them solve (i.e. make money, start a business, get healthy, lose weight, etc.). So now it's time to demonstrate your expertise and your wisdom to them. This will further cement you as an expert in their minds and THEY will convince themselves that YOU are the leader they want to JOIN and follow.
Remember, before your prospects will buy FROM you, they have to buy INTO you.
Second, Tastefully Offer a Solution - YOUR Solution
This is not the time to be timid. While you don't want to make the newsletter be a tasteless sales-pitch (because the goal here is to add value to the reader), you also don't want to miss out on an opportunity to make the sale.
You do this through strategically positioned sales copy (call to action - enticing and reminding the reader to purchase your product/opportunity to get even MORE value from you).
If your newsletter is doing all mentioned above AND it's incorporating some darn good copywriting (see Chapters 8 & 9 of the Attraction Marketing Formula on copywriting), the reader will be so in tune with your teaching, you will have not only captured their attention, but positioned yourself as the leader and someone they want to be with for the LONG HAUL.
When someone is unfamiliar with a concept, but see someone as a credible expert, they are more likely to follow that person than do their own research.
The reader is thinking, "yes, this author is talking to my pains, this author is proposing solutions, this author is an expert in the field and is definitely knowledgeable... I need to do what they are doing, to solve my problem."
Also... don't stop adding to your newsletter series.
The more value and follow-up emails you send, the more likely you'll catch your subscriber when the timing is right for them to join your team or buy your product.
Remember, it's up to YOU to keep that relationship going. So keep pinging your prospects over as long a period of time as possible.