If you're wondering what a sales funnel is, simply imagine a real-world funnel. At the top of that funnel, some substance is poured in, which filters down towards one finite destination. In sales, something similar occurs. At the top, lots of visitors arrive who may enter your funnel. However, unlike the real-world funnel, not all who enter the sales funnel will reemerge out from the other end. 

Imagine an autoresponder that doesn't just send emails, but allows you to track which channels your visitors are coming from, segment them based on actions they take and who they are (what they do in your funnels, how socially connected they are, what they purchase and more!), create custom follow up sequences (email, text messages and more!) for each visitor and FINALLY see the TRUE Lifetime Value of each of your customers!
In particular, if someone makes it through to the end of your landing page, you have a final opportunity to convince them to convert (incidentally, this is a good place for another CTA). With your closing argument/reinforcing statement, you should summarize everything you covered in the rest of your landing page and then throw in any additional selling points you think might seal the deal.
For example, when a customer finds you organically through a Google search for example, that means you have some element of authority. When you have authority, prospects are more likely to enter into your funnel because they know that if they found you relevantly, that whatever it is that you're providing must be of a great value. That's just the nature of SEO and organic search. 
The image above is a glimpse at one of my webinars that I created in LeadPages. I embedded my live webinar presentation into a webinar template in LeadPages and also added a chat box (not pictured) below the webinar so that attendees could communicate and ask questions. Webinar software can be very pricy, but this solution allows you to do them nearly for free by embedding a live Google Hangouts broadcast. LeadPages is a great option for anyone getting started with webinars.
Open-ended experimentation. This approach is similar to closed-ended experimentation except that more variations will be added for testing and experimentation will not stop when a winner is found. This method is used by large corporation to dynamically improve their conversion rates and improve user experience. Landing page can also be adjusted dynamically as the experiment results change to further enhance user experience.
When I first wrote this article in 2011, I mentioned how the marketing copy for Crazy Egg’s heat-mapping feature could have been stronger by better explaining how the tool helps customers to increase conversions. While this information is clearer now thanks to the detailed visuals and simple copy layout that allows the reader to skim and scan — it could be better by explaining a bit more.

Clickfunnels: Review, Demo, Pricing and Features: