We should have known this earlier. But this has been written lately by Evaldo Albuquerque who works at Agora Financial and sold over $80 million financiala products.
Maybe this is similar ot the AIDA ads designed for FB. Since most prospects are in a hurry and always scrolls their cp, they have no time nor patience to read long write ups.
The most important part of this letter writing is:
1. Know and align with the mission. Without the mission, you could not wirte a good copy;
2. Before and after
3. What prevented you from having this solution
4. What is the pain/gain offered by the product
I hope this works for you.