Media buyers had expected viewers to do some heavy sampling of ABC’s much-hyped, though critically maligned, new sitcom “Cavemen” in week one but also expected a dropoff in week two after the gawkers had satisfied their curiosity. And it looks like that’s exactly what happened.

“Cavemen’s” second outing averaged a 2.5 adults 18-49 rating, according to Nielsen overnights, down 24 percent from last week’s 3.3 overnight in its premiere.

The network’s “Carpoolers,” “Cavemen’s” 8:30 p.m. lead-out, also slipped 18 percent, from a 3.4 to a 2.8, though it once again grew out of its lead-in.

“Cavemen” got lots of attention leading up to its premiere because of its unique, and some argued absurd, concept. It’s an adaptation of the popular Geico commercials that featured cavemen being offended by the company motto, “So easy a caveman could do it.”

Media people felt the show would have a solid debut, because many viewers would want to see what was generating all the buzz, which was especially heavy online. But they also said the quality of the show was such that many would not return in the following weeks.

It remains possible that a chunk of “Cavemen’s” opening-week audience time-shifted the show, as digital video recorder ratings won’t be out for several weeks yet. Media people have cautioned that until the DVR ratings are out, it’s impossible to get a full picture of how a show performed because Nielsen’s DVR household sample has more than doubled since this time last year.

Meanwhile, another new show, CBS’s “Cane,” slipped among 18-49s for the third straight week, hitting a series-low 2.3 and trailing ABC’s “Boston Legal” for third place in the timeslot. That was down from a 2.5 last week.

Fox’s “House” was one of the only shows to rise week to week, from a 7.1 to a 7.3. NBC’s “Law & Order: Special Victims Unit” also jumped, drawing its best rating since Feb. 13 while dominating the 10 p.m. slot with a 4.9.

Fox led the night among viewers 18-49 with a 5.2 average overnight rating and a 14 share. NBC was second at 3.3/9, ABC third at 3.2/9, CBS fourth at 2.9/8 and Univision and CW tied for fifth at 1.4/4.
 
CBS began the night in the lead with a 3.4 at 8 p.m. for “NCIS,” followed by Fox with a 3.1 for “Bones,” up from a 2.9 last week. ABC was third with a 2.7 average for “Cavemen” (2.5) and “Carpoolers” (2.8), NBC fourth with a 2.2 average for “The Singing Bee” (2.1) and the first 30 minutes of “The Biggest Loser,” CW fifth with a 1.5 for “Beauty and the Geek” and Univision sixth with a 1.0 for “Amar sin Limites.”
 
At 9 p.m. Fox took the lead in a big way with a 7.3 for “House,” with ABC second with a 4.0 for its “Dancing with the Stars” results show. CBS was third with a 3.0 for “The Unit,” NBC fourth with a 2.9 for “The Biggest Loser,” Univision fifth with a 2.1 for “Destilando Amor” and CW sixth with a 1.3 for “Reaper.”
 
NBC led at 10 p.m. with a 4.9 for “SVU,” while ABC took second with a 2.8 for “Legal.” CBS was third with a 2.3 for “Cane” and Univision fourth with a 1.0 for “S.O.S. Sexo y Otros Secretos.”
 
Among households, Fox was first for the night with an 8.0 average overnight rating and a 13 share. CBS was a close second at 7.8/13, ABC third at 7.6/12, NBC fourth at 5.7/9, CW fifth at 2.0/3 and Univision sixth at 1.8/3.