Where do you live? In Norway it is very common having a unique lastname. Both my lastnames are very rare. One has 200 users, the other one 130. Both names are split between 2 families, so I have a 50% chance of being related to anyone I meet with any of those names. However, one of my lastnames, is very common in England and America(got it from English forfathers myself). The other one is unique for the entire world, as it's 100% norwegian. As far as I know, no one carrying the name have moved out of Norway and spread the name to other countries.