Hi Terence, first off I would like to say that an interesting and thorough review. The fact that you go into so much detail about Funnel hacks, both the pro’s and the con’s really makes me believe in it and you. It sounds like something I will definitely consider as soon as I get my own product to sell (which I am still working on at the minute). And if it works then it’s worth every penny I say.
A/B testing, or A/B split testing, is a method for testing two versions of a webpage: version "A" and version "B". The goal is to test multiple versions of webpages (e.g., home page vs. product page) or one specific element that changes between variation A and variation B (such as having a lead form on the left hand side or having it placed on the right hand side), FAQ to determine which version is most appealing/effective. This testing method may also be known as A/B/n split testing; the n denoting more than 2 tests being measured and compared. The data for A/B testing is usually measured via click-through rate or an alternative conversion tracking method.[11]
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.
It's no surprise Unbounce is near the top of this list -- they've actually written the book on creating high-converting landing pages. Although there are lots of amazing things about this landing page, the two that I absolutely love are: 1) The use of a chat window instead of a classic form, and 2) the detailed -- but well packaged -- information below the form.

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.