TV's Biggest Moneymakers

In Pictures: TV's Biggest Moneymakers

This time last year, CBS' The Mentalist seemed like just another crime drama in the pipeline. Without A-list talent or a franchise supporting it, advertisers saw little reason to shell out for the show. In fact, a 30-second spot on the freshman series commanded a hardly-impressive $107,000, on average, this season.

Twelve months and 16 million weekly viewers later, high-performing newcomers like The Mentalist--a top-five show in its first year--are poised to see their price tags soar. At the same time, reliable holdovers like News Corp. ( NWS - news - people )-owned Fox's American Idol will continue to fetch top dollar, while waning favorites like Walt Disney ( DIS - news - people )-owned ABC's Ugly Betty will likely take a hit.

In Pictures: TV's 15 Biggest Moneymakers

To determine which TV series generate the most money, we turned to TNS Media Intelligence, a division of Taylor Nelson Sofres that tracks ad spending. The New York-based firm provided us with networks' asking price, as of Jan. 31, for the season's 100 most-watched, regularly scheduled shows on prime time. For an apples-to-apples comparison of programs of differing lengths, the shows are ranked based on ad revenue per average half-hour.

No surprise, Idol takes the top spot on the list. Currently in its eighth season, the popular singing competition series lures some 6 million more viewers than prime time's second most-watched series, ABC's Dancing with the Stars, according to Nielsen Media Research. The result: The former notched an average of $623,000 for a 30-second spot, while the latter scored $205,000 for its results show (sixth place) and $196,000 its performance-filled nights (seventh place).

To be sure, these figures are estimates. The amount individual buyers have actually handed over for these spots vary, depending on such things as the advertisers' perceptions about the value of a show, the timing and size of their purchases and their clout with the respective network. Also factoring into the decision-making process this season: continued audience erosion coupled with a weakening economy.

In recent years, as much as 80% of these purchases are made ahead of the actual TV season, in what is known as the upfront marketplace. Accordingly, many of the purchasing decisions rely on anticipation, expectation and past results rather than actual in-season performance.

Take General Electric ( GE - news - people )-owned NBC's Heroes, a one-time hit that has since shed at least 2 million viewers a year. In fact, the high-concept sci-fi series garnered just 7.9 million weekly viewers so far this season, putting it 59th among network programs. As of late January, however, an average telecast still fetched $4.3 million worth of ads, making it one of the costliest telecasts in prime time.

"It's not necessarily just eyeballs that advertisers are buying here," explains Ed Gentner, senior vice president of video investment activation at MediaVest of advertiser interest. "It's the right eyeballs."

So while many in the buying community expect Heroes' spots to sell for less in the coming upfront given the audience erosion, they're quick to argue the show offers other perks for Madison Avenue buyers. Its viewers skew younger and male, both appealing to marketers, and the Heroes' audience is particularly engaged, with heavy online participation offered as proof.

New shows lacking track records are riskier purchases--and often cheaper as a result. Buyers are forced to rely on differentiators like night of the week (Thursdays are more desirable--and thus more expensive--than Fridays), casts and producers (established names help market a show) and companion series (highly rated companion shows lift a series' potential--and ad price).

But for every bargain-basement winner like TheMentalist, there's a pricey newcomer like Worst Week. Heading into the current season, CBS ( CBS - news - people ) was able to charge a premium for Week because of its Monday night placement, sandwiched in between the Tiffany network's highly rated comedies and the much-watched CSI: Miami. Despite failing to find an audience on par with either, the network reaps $2 million for a half hour's worth of ads, making it the 13th most expensive show in prime time. Location, as they say in real estate, is everything.

In Pictures: TV's 15 Biggest Moneymakers

TV Money Makers: American Idol