1. For a website optimization system comprising a processor and non-transitory computer-readable memory, a computer-implemented method for determining credibility of a website based on elements that determine a presentation of the website, the computer-implemented method comprising: identifying a plurality of related websites having a common set of elements, each website of the plurality of websites providing a different configuration for the common set of elements in order to produce a presentation that differs from a presentation of other websites of the plurality of related websites; receiving user input identifying credibility that a plurality of users attribute to each configuration for the common set of elements of each website of the plurality of websites; retrieving a new website that is related to the plurality of related websites, the new website specifying a particular configuration for at least one particular element of the common set of elements; and presenting a credibility score for the particular element of the new website based on the user input, the credibility score quantifying an impact that rendering the particular element according to the particular configuration has to credibility of the new website as determined by the plurality of users.
9. The computer-implemented method of claim 1 , wherein presenting the credibility score comprises presenting the credibility score adjacent to the particular element when rendering the new website.