The final stage of the sales funnel is the action that you're intending them to perform. In most cases this is the purchase. Again, how well you move them through the various stages is going to set you up with a specific conversion for this action. For example, if 100 people click on your offer and 10 people enter your sales funnel but only purchase people purchase, then you have a 2 percent conversion. 
We’ve written a bit about defining your target audience, but suffice to say that if you still haven’t done this, then don’t bother moving on to the next steps in the sales funnel. You must have some idea of what people are interested in your topic, where they are hanging out online and what motivates them in order to begin creating awareness of your course at the top of the funnel.  If you just start sending out emails and tweets willy nilly with no real plan, your efforts (and you will read later on that it is a lot of effort) will be wasted.  You need to know that you are creating the right content for the right people.
One of the core concepts in the digital marketing industry is the sales funnel. While odd sounding at first, this single core concept can take a business from virtually non-existent and unknown to multi-million-dollar marketing machine with mass saturation, seemingly overnight. In fact, there are skilled practitioners who have built a career around implementing this single concept in business.