Conversion funnels are the paths taken by your visitors, measured from their original click through to your website (referral) all the way to when the complete the checkout process.
Due to the fact that lead generation style website typically do not require many (if any) clicks to get from the original referral landing page to the final call to action, which is probably a free quote form or phone number, conversion funnel is a term typically used only in Ecommerce.
Conversion funnels are always slightly different from store to store. However, there are a few aspects which are likely to stay the same across the board.
A conversion funnel works as follows:
Because of the unique qualities of many Ecommerce platforms, these steps are will probably differ from time to time. Also, the page which the user was originally linked to will play a role in the path they take through the store to find what they are looking for.
Web metrics software such as Google Analytics and KISSmetrics has the capacity to provide mountains of data relating to your conversion funnels. How you choose to action this data to improve the profitability of your business is totally up to you.
Firstly, take a look at the visitors that are not converting. Where are they coming from? Are they coming from a Google AdWords campaign? If so, what can you do to optimise that campaign so it is generating more qualified traffic?
Secondly, navigate through every path which could be taken by your visitors. What are they seeing on the landing page? If it is not compelling enough for users to continue through the site, consider using the readily available techniques to optimise it. From this point you should navigate through the rest of the conversion funnel. Again, when a page is not compelling enough, FIX IT. When something is not working or totally confusing in the checkout process, FIX IT. Run as many A/B split tests as it takes to get the most from every paid or unpaid click.