Failure in getting marketing results is usually either a failure of strategy or it's a failure of execution. 

And by execution, I mean the tactics. Those are the two sides of marketing - strategy and tactics/execution. 

To get strategy right, you need to understand 3 things:

In the podcast a breakdown Walmart as an example of strategy.

Now tactics is a different thing. For some folks where everything falls apart. Tactics is the actual building of the campaigns. It's building the website, it's building the lead funnel. It's generating traffic. It's doing a/b split tests, sending email, creating direct mail, running billboards, whatever happens to be appropriate for your business.  That is the work of marketing and for many folks that haven't been successful in marketing, the reason that they haven't been successful is because they have been busy doing the work of the tactics (the execution) without first doing the strategy.