Your marketing persona is something generally overlooked. Just like a character in a movie, you must define who you must come across. There is no requirement that your persona to be autobiographical. It can be your best self if that you desire or it can be fictional. It is completely legal and moral, just like books have fictional characters.
Before you write your story, define who are you and make sure that this comes as congruent with your marketplace. If I am writing a copy on a self-defense product, my marketing persona is a combination between Jason Borne and a 6.5 feet German who doesn’t talk much. If I am writing a copy on dating, my marketing persona is the loser who found the solution to dating and change his life around. Now he has a girlfriend and even if she leaves, he knows how to get one right away.
The most important thing when it comes to your marketing persona is that it must make sense in the context. I don’t want to learn from a very handsome person how to pick up girls. I want to relate. I don’t want to learn from an Yale educated person how to earn money online. You’re from Yale dude, I’m not. At the same time, it must come across as credible in the terms of benefit delivery. If you are 4.2 feet and you’re 110 pounds wet, don’t teach me about self-defense. You can have the best argument but it will seem as fake (which is ironic as there are many 4.2 feet, 110 pounds that compete in street and cage fights).
Think of it like a movie. You expect the action hero to look and behave in a certain way. If he must save the world you’re expecting a military buzz cut, to move with confidence, to be the strong silent type. You’re not expecting the team from “Revenge of The Nerds” to do deep undercover spy work in Vienna.
Writing good copy has a lot in common with writing a good movie script. It comes down to authenticity and congruence. It is the place to get what you expect. For example, while I can play the piano to some degree, I wouldn’t use the image of a bearded guy at 6.2, wearing denim and leather clothes, never smiling and with a penetrating look as someone to sell a piano course. It must be someone a lot more gentle and sophisticated, to fit the rule.
This is generally a high level concept. I’ve learned it from Clayton Makepeace and honestly, I haven’t heard it in many copywriting products. He repeated several types on the importance of selecting the right spokesperson for the product, so if that person would be in front of you, it would make 100% sense to sell the product. John Carlton also brought it in SWS but that’s about it. The key to remember here is that people buy from other people who fit the role.