What should a copywriter know?

Bingo!

 

You should also write as you have something valuable to offer to your customer. Why would they want to buy from you? What can you offer that your competitors can't?
You must create the desire to buy. The reader must think "I need this for me. This is what I always wanted."
You must put him at ease, and show him all the improvements he'll experience in his life with your product and all the inconvenients he currently suffer because he doesn't have it now.

 

There are many crucial elements to great copy, but this is what I consider the central theme of effective copy. When I am writing I also recognize that I am more often on the receiving end of a pitch. Nothing makes me tune out faster than the feeling that I'm only valued as a potential dollar sign. I'm certain that a great number of fellow readers feel the same way.

 

Copywrite law, unless you like getting sued.

 

You better heed SARubin's advice if you're a copywriting noob who'd like to make it big! He gave some pretty solid advice. (Applauds)

 

Here's something more.

To truly understand how to write copy to sell find the sales letters that motivate you to buy the product they market. Then dissect those letters to discover what exactly in them does that motivating. How are they worded and how are the words laid out that makes you want to buy.

When you understand the techniques used in the great letters you understand how to effectively write copy to influence.

 

I like SARubin's list.

I would add that you should know grammar as a copywriter. Sure, you don't need to be a master at it, but not knowing basic rules can turn off clients. Grammar is how we communicate effectively. Without knowing it well, you can cause confusion, and with copywriting, you want to be precise.

You might have to understand how to work marketing software. If you manage the copy & optimize it, you should know how to do testing. Not everyone does this though. Some copywriters send over the text files as their only deliverable.