Funnels are fundamentally about two things, getting the right mix of website traffic, and widening the funnel to get as many people to the bottom (conversion) as possible. The process of widening and moving more people down the funnel is really important. So it becomes less about getting more traffic, and more about converting the existing visitors. Some great tools for this are: Crazy Egg, Snap Engage, Optimizely.
The truth? People are smart. They're not simply going to buy anything from anyone unless they feel there's an immense amount of value to be had there. Thus, your funnel needs to built that value and bake it in through a variety of means. But most importantly, you have to create a strong bond with your prospect, and that happens by being relatable, honest and transparent in your email warming sequence.
Prospecting and marketing are all the things you do to get people into the first of your sales funnel stages. Note that stages are broken into two or more steps wherever possible. A demo could be called a single stage, but in real life it involves a lot of things: contacting the customer, sending reminders, doing the demo, and then following up. Whatever your own sales stages look like, the support you need in managing them will be the same.