Copywriting is using words to get people to give up their money in exchange for services or products. In other words, it is “salesmanship in print.” as defined by John E. Kennedy back in 1904.
The copywriting should be all about the consumers so the copywriter have to talk about them, talk about the problem, the promise, the proof, and the proposal to solve the problem. The copy must be useful and valuable. No copy is too long, too short, only too boring. Write about the preponderance of proof so the consumer have to make a decision.
Here's a six-part framework (PASTOR) for writing better sales copy that Ray Edwards mentioned:
P = person, problem, pain.
A = amplify the consequence of not solving the problem.
S = story, solution , system.
T = transformation, testimony
O = offer
R = response