I think Ellis has a long, long way to go to approach Gaiman in terms of fame. Anansi Boys debuted at #1 on the NYT charts and the Graveyard dominated the children's books charts for a long while and won a slew of awards.
Yep. Plus, of course, the fact that Stardust, Coraline and Beowulf were pretty successful movies, a Graveyard Book film is on the way and so is an HBO series based around (the NYT bestselling) American Gods. Gaiman is also a hugely successful writer of children's books. But then remember, this is The Nacireman you're dealing with: his relationship with reality is tenuous at very best.