A unique, uncommon last name is as good as gold, when trying to find a person; and any last name with a history of locations that a person has lived is even better.
An uncommon last name can be used to do a last-name-only people search on WhitePages.com or DA Plus to find possible relatives for a person. All you have to do is leave the “First Name” field blank on your search. Even someone with a common last name and a history of living in smaller or rural areas can often be located this way. However, a common last-name-only search for large cities will usually return too many results to be useful. You would have to call too many people before you would likely find a relative of the person you are searching for.
In addition, the WhitePages.com people search allows you to search all states at once. So even if you don’t know past locations and addresses for a person with an uncommon last name, you can search all states at once to find the person or possible relatives to contact. Again, this will only work with uncommon last names, since common last names will return too many results to be useful.
Good luck with your people search and web search efforts.