• by David Goetzl  @dgoetzl, June 20, 2013

Demand for national TV time looks to have been relatively healthy last month. Either that or deft inventory management seems to have been in play at the Big Four broadcasters.

By one measure, prime-time ratings were flat at NBC and down precipitously at the other three majors. Yet, combined ad spending by media buyers Aegis, Havas, Interpublic and Publicis -- across all dayparts -- increased at all four networks.

Compared to May 2012, spending jumped 18% at ABC, 14% at CBS, 9% at NBC and 2% at Fox. The data comes from Standard Media Index (SMI), which tracks spending data that represents about 60% of all agency spend. (WPP and Omnicom are not tracked).

SMI Chief Commercial Officer James Fennessy said ABC had a “significantly higher percentage of scatter dollars than the other networks” and it “quickly capitalize(d) on improved audience share with uncommitted dollars from advertisers and their agencies.”

SMI data would seem to offer the most accurate macro-portrayal of the ebbs and flows in the ad business since its data is captured directly from ad booking systems.

In May, the Big Four all saw spending increases for the second month in a row, a sign that the ad economy might have undergone a spring bounce. For each network had little to brag about during this year’s first quarter.

NBC, for example, saw year-over-year spending declines in January, February and March – including by 66% in February as it finished behind Univision in the sweeps race. Fox was flat in January and down by 15% and 29% in February and March, respectively.

CBS had declines of 3% in January and 9% in March. It was up 108% in February no doubt mostly because of the Super Bowl.

ABC arguably fared the best with 1% growth in January and 5% in February, but that was followed by a 5% drop in March.

Since the figures cover all dayparts, ABC may have benefited from the surge at “Good Morning America” and the shift of “Jimmy Kimmel Live” to a more favorable time slot. NBC’s big drop in February was certainly hurt by the absence of “The Voice,” which didn’t debut its spring season until near the end of March this year. A weakening “American Idol” certainly didn’t help Fox.

Network TV as a whole followed the Big Four’s general trend of a rough early year, followed by a solid April and May. For the top-10 networks combined, year-over-year spending dropped in each of the first three months of 2013 -- then jumped 13% in April and 11% in May. 

Still, even as the Big Four have showed improvements, that doesn’t look to have translated to the current upfront with Fox reportedly bringing in a 10% volume decline and CBS coming in flat.

With all the talk about the surge in cable, the SMI data shows that in May the broadcast networks as a group performed better than a big subset of cable. The top-10 broadcasters were up the 11% in dollars, while the top-20 cable networks fell a combined 5%. 

But over the first five months of the year combined, cable’s 4% increase tops the 1% broadcast gain. Cable’s year-to-date share of TV ad dollars is also at 25.8%, while broadcast is at 23%.

(Some would argue it’s an unwieldy comparison to even entertain since cable hits don’t always run around the same time each year. Also, the SMI data picks up many more hours with the cable networks.)

With individual networks, the NBA playoffs may have helped ESPN in May as it posted a 20% increase, though TNT was down 8% with its games. (The number of games each network had and appeal of the teams could have been a factor.)

TBS, however, was up 10%. USA topped all others last month with a 26% gain, beating Nickelodeon’s 23%.

NBCUniversal had two trouble spots, however, with Bravo spending falling all five months this year, including by 14% in May. E! has fallen four out of the five months and 20% last month.

Viacom had mixed May results with Nick up nicely, MTV up 4%, but Comedy Central was down 4% and Nick at Nite fell 8%. At Discovery Communications, the Discovery Channel was up 10%, while TLC was down 2%. The only News Corp. network in the top 20, FX, was up 6%.