Twice as many people vote for Idol than watch it?

This does not compute:

"As the final five contestants on “American Idol” competed for a chance at the top prize on Tuesday, Fox once again took first place in the night’s ratings.

According to Nielsen’s estimates, 22.5 million viewers tuned in to the reality show during the 8 p.m. hour, easily more than any other program on Tuesday" (from New York Times)

According to our pal Ryan Seacrest, over 45 million votes were cast for this week's vote-off. Can anyone explain the discrepancy? First of all I really doubt that the majority of viewers vote at all. My guess would be that at most one in 4 vote. Which would imply that each one voted an average of 7+ times. Where's the fish?Technorati Tags: american idol, seacrest, fox, tv