Writing Copies

How long should your copies be? 

As with most things in life, it depends. But I always like to start by writing as if I were writing a classified. 

What’s the offer? What action you want me to take? And when should I act? 

“Join my dance class now. Lose weight”. 

Writing a classified makes you pay by the word

7 words, 1 promise and 1 action. I know this might not make the cut (unless I’m the only one running the dance class in here). 

May be I want to add a social proof. Throw in an offer to create urgency. Back up my claims. 

Slowly but carefully I add blocks to my classified. 

I will try and keep it as long as it needs to be. Not any longer or shorter. 

Thoughts?