Here we have an example of an open head, where there is room for something NEW !!
And that any text can be turned into a saleable one - even those long, discouraging e-mails, which some people do not like. This particular client bought it, as she herself wrote: "I only read in the newsletter that there is and what is in it. Now see, we have two extreme reactions to the same text. If we wanted to please everyone, we could have get confused.
I think you happen to wonder what to write, and in your head you have 'how to please the readers?
In my opinion, writing to please the readers is a mistake. Well, unless you work in a circus.
If you are going to sell - focus on selling! This makes business very simple. And let go of the idea that you will sell to people with their heads closed. Because there are always these thoughts: oh dear, somebody has signed off, I have lost my best info-soruce-customer EVER....