This is from EarlyToRise:

1) A good understanding of why and how people buy things.
2) The ability to make a big, tempting promise.
3) The skill to show that promise as a picture, to advance it with propositions
and to support those propositions with proof.
4) The ability to distinguish between features and benefits.

What would you add to the list? I’d add 2.5) The ability to follow up on your big, tempting promise…

I think #1 is the most important

Lewis