1. A computer-based method of search term ranking, the method comprising: receiving a corpus of search terms forming a database index and storing in a computer memory; comparing the search terms in the database index to search terms identified within a page to generate a target list; generating a frequency count of the number of times that each of the search terms is used within the page; determining a density by dividing the frequency count by the total number of unique search terms found in the page; calculating the prominence of a search term by sending an instruction to a processor to create an array in the computer memory of a value representing the frequency of each search term and a value of the placement of each search term; sending an instruction to the processor to identify the prominence value through dividing the frequency value of a search term by the value of the placement of the search term, wherein when the prominence value is at least 0.6, the prominence is high, creating a ranking of the search term by sending an instruction to the processor to create an array in the computer memory of the values of each search term's density and prominence; and sending an instruction to the processor to use a logical computation to compare the values in the array of each search term's density and prominence values against a median density held in a separate array, wherein when the target list term density is greater than the median density and the prominence value is at least 0.6, the ranking of the keyword is primary, and wherein each of the steps is performed by one or more processors.