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.
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.
Significant improvements can be seen through testing different copy text, form layouts, landing page images and background colours. However, not all elements produce the same improvements in conversions, and by looking at the results from different tests, it is possible to identify the elements that consistently tend to produce the greatest increase in conversions.[citation needed]
In online marketing, a landing page, sometimes known as a "lead capture page", "static page" or a "lander", or a "destination page", is a single web page that appears in response to clicking on a search engine optimized search result or an online advertisement.[1] The landing page will usually display directed sales copy that is a logical extension of the advertisement, search result or link. Landing pages are used for lead generation. The actions that a visitor takes on a landing page is what determines an advertiser's conversion rate.[2]
The messaging on the page reinforces the reason for their click, reducing or removing confusion and therefore increasing conversion rates. This improves overall user experience and reduces the bounce rate (individuals leaving the site without converting or navigating to another portion of the site) for the page. Good message matching can increase conversion by up to 50% in many cases.[13]

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.