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.

Total-experience testing, or experience testing, is a type of experiment-based testing in which the entire website experience of the visitor is examined using technical capabilities of the website platform (e.g., ATG, Blue Martini Software, etc.). Rather than creating multiple websites, total-experience testing uses the website platform to create several persistent experiences, and monitors which one is preferred by the customers.[citation needed]
Imagine an autoresponder that doesn't just send emails, but allows you to track which channels your visitors are coming from, segment them based on actions they take and who they are (what they do in your funnels, how socially connected they are, what they purchase and more!), create custom follow up sequences (email, text messages and more!) for each visitor and FINALLY see the TRUE Lifetime Value of each of your customers!
Marketing experts recommend websites remove the navigation menu and limit internal and external links on the page.[7] The form length mirrors the value of the offer[clarification needed]. They may also include a relevant image, animation or short video. These pages also tend to contain small icons (i.e. of Facebook, or Twitter) to facilitate social media sharing.
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.