1. A method of ranking local search results based on reviews by experts, the method comprising: receiving a query from a user via a user device; identifying a geographic area and a category of business for the query; identifying, with one or more processors using reviews related to the geographic area and the category of business from a plurality of users, a plurality of experts within the plurality of users based at least on respective numbers of reviews each user submitted, including iteratively modifying the category of business to identify at least a threshold number of experts; ranking, with the one or more processors, local search results responsive to the query based on reviews of the local search results by the plurality of experts; and causing the ranked local search results to be displayed via the user device.
7. The method of claim 1 , further comprising: identifying reviews for the geographic area and business category that are shorter than a threshold length or that have less than a threshold quality score; and removing those reviews determined to be shorter than the threshold length or to have less than the threshold quality score from a list of reviews used to identify an expert.