How popular is Tolkien? Many consider him to be the leading story teller of the 21st century. His books have been read by millions. Movies on his books are amongst the top grossers of all times. A quantitative measure is the number of pages Google indexes for various middle earth terms. So I did some googling and came up with these reults.
In comparision some other fantasy writter have these many pages referencing them.
Please notice that the last two terms have been quoted before searching. This had to be done because frank/herbert are common names and all references will not necsessarily refer to the writter of Dune. But Tolkien is such an uncommon name that it usually will be reffering to the writter.