Unique visitors instead of total visits — If you're counting every visit in the denominator of the equation, you're including return visits too. This doesn't make sense if someone can only convert once (e.g. signup for an account). Consider how they might check out the site a few times before converting. If so, don't let that deflate your conversion metric. Instead, count the unique number of visitors in any given period. And make your period at least as long as the average time it takes for someone to convert after first visiting your site.
Cons: They offer several paid levels but honestly, the paid or Free plan offer a limited package and all of them will funnel you to the main plan. . Now this is just for your funnel builder and not your hosting or CRM. For half the amount I can outsource and build landing funnels that I own. The main focus of this is for small business and solopreneurs. . Now it is if you can put the software to use and turn sales. But if you are just starting out this will kill the cash flow. Additionally. I found that a lot of creativity and design are needed. So be prepared that to make this work it takes time. I found it to be very time consuming and not the 5 minutes they claim.
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. 
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.

Clickfunnels: Review, Demo, Pricing and Features: