What I think he means by "if you have coding as a secret weapon" in this case would be, if you are a Marketer that can code as an extra, you will be highly valued.
I am a marketer who can code in a rudimentary manner. I've done projects on a shoestring budget that have netted companies thousands of new customers and hundreds of millions of dollars.
What helps is that even if I can't code the entire project, I do know how to properly source and manage people who do. I have enough of an understanding to respectfully manage all the business and technical partners in a marketing project -- and help them work together in a way that produced a better sum of the parts.