'American Idol' 2006 winner Taylor Hicks

'American Idol' 2006 winner Taylor Hicks

A 30-second ad on "American Idol" will cost you somewhere in the neighborhood of $600,000 this season, making the show once again the most expensive series on television.

The FOX ratings juggernaut has held that title for three years running now, and it's far and away the priciest show for advertisers. No other show commands even $400,000 for a 30-second spot, according to a survey of agencies who buy ad time conducted by Advertising Age magazine.

The Wednesday "Idol" results show is the more expensive of the singing competition's two weekly installments, commanding an average of $620,000 per 30-second ad (some commercial spots closer the May finale are going for up to $700,000). The Tuesday performance shows are only slightly cheaper at $594,000 per ad.

That "American Idol" is so expensive is not a surprise: It was the highest-rated show on TV last season in both total viewers (better than 30 million per week on both Tuesday and Wednesday) and among the demographics that make advertisers salivate, adults 18-49 and adults 18-34.

FOX is also counting on an "Idol" halo effect for its comedy "The Loop," which will follow the Wednesday results show come spring. "The Loop" drew pretty meager ratings last year on Thursdays, but its new timeslot allows it to fetch ad prices of $310,000.

ABC's "Desperate Housewives," which began its third season with solid numbers Sunday, is No. 3 in the Ad Age survey, with ads costing $394,000 apiece. CBS' "CSI" is charging $347,000 per spot, a little bit more than "Grey's Anatomy" ($344,000), which beat the crime drama in their initial head-to-head ratings battle last week.

The most expensive new show (aside NBC's "Sunday Night Football") is ABC's "Brothers & Sisters," weighing in at $242,000 per ad in the post-"Housewives" spot on Sundays. The cheapest program on the schedule is NBC's Saturday edition of "Dateline," where ads cost a mere $45,000.

Here are the 10 most expensive shows in the Ad Age survey:

1. "American Idol" Wednesday (FOX): $620,000
2. "American Idol" Tuesday (FOX): $594,000
3. "Desperate Housewives" (ABC): $394,000
4. "24" (FOX): $364,000
5. "CSI" (CBS): $347,000
6. "Grey's Anatomy" (ABC): $344,000
7. "Sunday Night Football" (NBC): $342,000
8. "Lost" (ABC): $328,000
9. "The Loop" (FOX): $310,000
10. "Survivor: Cook Islands" (CBS): $296,000