By Jessica Toonkel
(Reuters) - The Democratic presidential candidates prime-time debate on CNN attracted a record 15.3 million viewers but the audience fell shy of those for recent Republican debates, the network said on Wednesday.
The figure, based on Nielsen data, was smaller than the 24 million and the 22.9 million viewers who watched the first two Republican debates, shown on Fox News Channel and CNN respectively.
Prior to last night's debate, the highest rated Democratic presidential primary debate on cable news was CNN's 2008 showdown between Barack Obama and Hillary Clinton, which averaged 8.3 million viewers.
CNN charged advertisers $100,000 for a 30-second ad during last night's debate, compared with $200,000 for the Republican debates in September, according to people familiar with the situation. That compares to around $4,000 and $6,000 for a typical primetime ad on CNN, according to another person familiar with the situation.
It is not surprising that the Democratic debates did not have the same level of viewership as the Republican debates given that the Republican debates "have a well known list of characters," like Donald Trump, said Barry Lowenthal, president of The Media Kitchen, a New York-based media buyer.
While people know Clinton and U.S. Senator Bernie Sanders of Vermont, they are less familiar with the other candidates, Lowenthal said.
"You don't have the same kind of draw with the Democratic debates as you did with the Republican ones," he said.
Almost five million 25 to 54 year olds tuned in Tuesday night, marking the highest number ever for that demographic in a Democratic debate.
