American Idol is on its way to becoming a TV phenomenon -- as big, maybe even bigger than -- Survivor.

Ratings for Idol's second episode show that roughly 25 million people tuned in.

That's a huge number for any type of TV show and more significantly, moves into that rare territory when it becomes a cultural touchstone rather than just a passing fad.

"This show is not a flash-in-the-pan -- it's Fox's Survivor," said Mediaweek analyst Marc Berman. "If Fox plays its cards right they can have a long-term franchise. They can't overkill it."

So just how big is Idol?

Tuesday's second-season premiere notched nearly 27 million viewers -- the best opening night for a TV show all year -- and, except for a handful of Survivors, the highest rated reality show in TV history.

American Idol has something else going for it that many of the other "reality" shows don't -- heart.

"That's the beauty of the show, Berman said. "It's not just reality, it's a drama of people creating their own little world, like Survivor.

"These people all have their own stories. It's not just about people competing.

"In the first American Idol, we really wanted to get to know Kelly, Justin and the others," Berman said.  "And that's something that a show like Fear Factor will never have."

Wednesday's Idol episode crushed its reality-show cousin, ABC's The Bachelorette, in head-to-head competition (8:30-10 p.m.) nearly doubling The Bachelorette's viewership.

It also nearly tripled the viewership of a West Wing repeat on NBC and, like Tuesday's Idol, helped Fox notch its best-ever Wednesday prime-time numbers (barring sports).

And Wednesday's pre-Idol 2 episode of That '70s Show on Fox scored its most viewers in over a year.