1. A computer-implemented method of determining whether a business listing is legitimate, the method comprising: accessing, by a processor, a list of legitimate business titles, each legitimate business title including two or more words; generating, by a processor, a matrix of surprisingness values by: examining each legitimate business title to identify pairs of words occurring in that title, adding a count value to the matrix for each pair of words identified, such that the matrix includes a plurality of count values for different pairs of words occurring in the legitimate business titles, and normalizing the plurality of count values for the matrix to generate the matrix of surprisingness values, where each surprisingness value of the matrix of surprisingness values indicates how unlikely a pair of words are to appear in a legitimate business title; storing the matrix of surprisingness values in memory; accessing a plurality of business listings each associated with title data including two or more words; selecting a particular business listing of the plurality of business listings; determining a surprisingness value for the title included in the particular business listing based on the matrix of surprisingness values stored in the memory; and determining whether the particular business listing is legitimate based on whether the surprisingness value for the title included in the particular business listing is less than a threshold value.
2. The method of claim 1 , further comprising associating the surprisingness value for the title included in the particular business listing with the particular business listing.