Webflow, a design tool for web developers, packs a lot of information into just a GIF and three form fields. Having the entire sign-up form on a single line is a nice touch here -- not only does it make the page shorter, but filling out each box from left to right shows users how close they are to clicking the fourth blue button and getting started for free.
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.