Why is it so popular?

Whenever an anime gets popular I always blame it on the localization and the exposure to the NA masses. eg. Naruto! Full Metal Alchemist! Bleach! and whatever, even though most anime are popular before they ever get ported here.

Although, Inuyasha strikes me as sort of odd. I don't intend to follow it, but if I ever come across it while channel surfing then I get addicted to the episode and watch for the rest of the time that it's playing. It's so corny too since it's so easy to pick a random time to scream "Kagome!" and you'll have shouted it within 5 seconds of Inuyasha himself.

Maybe it's easy to get into without needing any prior knowledge. I've seen the Wind Scar so many times, and know of Naraku escaping death constantly, and I've never intentionally watched the show!

Jam it back in, in the dark.