A method for displaying an advertisement includes storing, in a database, a plurality of keywords wherein each keyword in the plurality of keywords corresponds to a product or service, assigning a priority value to each keyword in the plurality of keywords, analyzing a webpage to identify a plurality of words displayed by the webpage. selecting a word in the plurality of words based on the assigned weight value, comparing the selected word to the plurality of keywords to obtain at least one matched keyword, selecting at least one keyword from the at least one matched keyword based on the assigned priority value, and modifying the webpage such that when a user of the webpage interacts with the selected word displayed by the webpage, an advertisement for the product or service corresponding to the at least one keyword is displayed.