By page rank i take it for granted that u r referring to page rank while searching for particular item that your website is also selling!
Well the answer is if u have heard of keywords then your job is easy!! Keywords are nothing but words for particular object that different type of users type for particular object!
e.g. For flower pot u type flower pot, other person might type flower vase, or some other might type flower case, etc.
Search for keyword software on google! U will get your answer!