At name statistics you can see how popular your first and last names are.

Dan is #179 (and Daniel is #12) on the most popular male names list, but Hersam is “a very rare last name.” In other words, it’s not in their database.

Having a rare last name can be nice because I don’t have to compete with people for domains or usernames and I am the #1 result on Google. Then again, if I didn’t want to be found that could be a bad thing.