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.
Hi Andrey, it is definitely not for beginners who have no idea how to even make money online at all. If you have a business already, funnel hacks is definitely something that you should invest in. I would say that there are definitely better and more affordable options for beginners too. Paid traffic is a tricky thing, but Funnel Hacks actually break it down easily on how to do it quickly.
Full disclosure: IMPACT is a HubSpot partner -- but that's not why they're included here. IMPACT's landing pages have long been a source of design inspiration. I love the simple layout of the page, from the large headline copy and detailed featured image, to the outline that surrounds the form, to the colors and fonts that are very pleasing to the eye.
Trulia did something very similar to Bills.com 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.
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.