The metaphor of the funnel is used because people drop away at each stage of a long sales process: for example, many of your unqualified prospects may have existing suppliers with whom they're very satisfied. Others may have needs which other competitors are better-placed to satisfy. Still, others may love your products, but not have the budget to buy them.
Trulia did something very similar to with their landing page. It starts with a simple form asking for "an address" (which sounds less creepy than "your address," although that's what they mean). Below this simple form field is a bright orange button that contrasts well with the hero image behind the form, and emphasizes that the estimate will be personalized to your home.
Landing page optimization (LPO) is one part of a broader Internet marketing process called conversion optimization, or conversion rate optimization (CRO), with the goal of improving the percentage of visitors to the website that become sales leads and customers. A landing page is a webpage that is displayed when a potential customer clicks an advertisement or a search engine result link. This webpage typically displays content that is a relevant extension of the advertisement or link. LPO aims to provide page content and appearance that makes the webpage more appealing to target audiences.

Very comprehensive review of funnel hacks. I’m glad to see that you actually have it and honestly review it. The cost is rather high, and I think it may not be the best for beginners. i think they may be overwhelmed with funnels if they are just starting out. However, if they have the cash and time to invest, I’m sure that it would benefit them greatly.
I'm not sure how the algorithm works (or if there's one at all), but while I was filling it out, I had some anxiety about not qualifying. Once I found out I did, I was excited to fill out the form, which I'm sure most people who are in debt and using this tool are. By making this offer seem more exclusive before the form appeared on the landing page, I'd bet that increased conversions pretty significantly.