Tolkien himself found one possible reason, in Letter 324, for this common mistake: association with yiddish. The name "Tolkien" is German of origin ("tollkühn" = "foolhardy"). At the time, Jewish names were often associated with German; as such, some people might have molded it after the German "-stein".
- The poem "Goblin Feet" is written by a mister Tolkein.
- More advertisers chose "Tolkein" as their keyword on Google Adwords than "Tolkien" - because the former is cheaper.