By Lynette Rice
Updated March 14, 2013 at 06:26 PM EDT
Nightline Kimmel Logo
Credit: ABC

Jimmy Kimmel’s much-anticipated move to the 11:30 p.m. timeslot on ABC has generated great buzz — along with a tidal wave of good press and favorable reviews — but the impact of such a change has yet to produce dramatic results for the fourth place network. To wit: Kimmel’s performance during the February sweeps month was actually lower than what Nightline did from 11:30-midnight in February of 2012.

According to live plus same day ratings from Nielsen, Kimmel was down 12% in adults 18-49 (1.007 million versus 1.143 million) and 25% in viewers (2.883 million versus 3.828 million) compared to what the news magazine averaged last year. ABC has long argued that by moving Kimmel to the earlier timeslot, it can make more money off of commercials because advertisers prefer entertainment programs over news. In the suits’ terms, the costs per mille (that’s thousand in Latin) among adults 18-49 can sell for a premium if they are within “quality” entertainment, which is why Kimmel — according to one high-ranking ABC suit — sells out far better than Nightline ever did.

So how’s Kimmel faring versus the competition? There’s no doubt about it, the folks at NBC and CBS are keeping a keen eye on the new young guy at 11:30 p.m. But Jay Leno’s popularity — as confounding as it is to critics and Kimmel, especially — remains strong: The Tonight Show beat Jimmy Kimmel Live and The Late Show with David Letterman in the February sweep among adults 18-49 (1.003 million versus Letterman’s 920,000 and Kimmel’s 898,000). Leno also attracted a bigger audience (3.5 million viewers versus Letterman’s 3.2 million and Kimmel’s 2.5 million).

Over the last two months, however, all three shows have earned bragging rights. Often times, the power shifts weekly: During the week of Jan. 21, when Letterman was in repeats, Kimmel averaged a larger audience than CBS and better ratings in adults 18-49. But Kimmel also out-rated Letterman when he was in originals, like during weeks of Feb. 11 and Jan. 14. For now, though, beating Leno is the toughest task for the feisty Kimmel: After dominating during his premiere week of Jan. 7 (1.07 million 18-49 viewers versus Leno’s 1.04 million and Letterman’s 820,000), Kimmel has yet to do better than his NBC counterpart when he’s in originals. In fact, during the week of March 4, when Kimmel was in originals (except for Friday) while Leno and Letterman were in repeats, Kimmel was third in viewers (2.5 million) versus NBC (2.8 million) and CBS (2.6 million). He tied Leno in 18-49 with a .7. (Letterman got a .6).

Despite the ratings, published reports have claimed a succession plan is already in the works at NBC that involves replacing Leno with Jimmy Fallon in 2014 — though one insider insists that late night is the last thing to worry NBC execs, especially given their woes in prime time and in the early hours, where Good Morning America continues to butt kick Today. And any kind of hit that Leno has taken or will take in the near future has to be blamed as much on the poor performance of his prime time lead-in as it does the new competition from Kimmel. Replacing him with a younger guy like Fallon may not be solution – but it’s sure going to be fun to watch what happens over the next several months. We’ll stay tuned.