Viacom — “and pretty much only Viacom” — is engaged in a systematic program of “ad stuffing” even as ratings of its networks continue to decline, according to a report by Wall Street analyst Todd Juenger.

Backed by what he called “photographic evidence” (i.e., photos of a TiVo programming guide), the Sanford Bernstein analyst documented widespread extension of shows’ customary running times. Only one other network he studied — NBCUniversal’s Syfy — attempted a similar move, though that was an isolated case in the wee hours of the overnight period.

Viacom’s extra episodic minutes, Juenger claimed, are filled with ads, even on Viacom’s flagship networks and even during prime time. And the spots are airing even as ratings ebb, he noted. Nickelodeon, Juenger said, saw its ratings drop 26% last week and has posted downturns of 20% or greater in all but three weeks of 2018. MTV, which Juenger said did not stuff extra ads into prime time, has had a rosier ratings picture. Its four straight quarters of year-over-year ratings growth are the network’s best streak in seven years, with particular strides in the 18-to-34-year-old demo.

Paramount Network, Juenger said, has run 71-minute episodes of the ostensibly hour-long reality show Bar Rescue and 38-minute installments of the classic sitcom Friends. Those bloated blocks came after the former Spike network relaunched in January with a commitment to trim its ad inventory by 30% during its original scripted programming hours. (Then again, a report by Pivotal Research earlier this year ranked Viacom as the most ad-heavy programmer among those tracked by Nielsen, with an averaged of nearly 15 minutes of commercials per hour.)

“We find this behavior especially frustrating relative to the narrative, which some investors have adopted, that Viacom is in the midst of some kind of positive momentum, a ‘turnaround,'” Juenger wrote. “Networks with momentum don’t stuff an extra 10 minutes per hour of ad time.”

Viacom declined to comment on the report when reached by Deadline. Its stock didn’t react to it, gaining a fraction during the trading day to close at $30.21. While Juenger is a respected, veteran analyst, he has been consistently and sometimes stridently downbeat on many cable programmers, especially Viacom. In that sense, the report — which was bluntly titled “The Ad Stuffing Palooza Continues” — was not a change of course. Juenger currently has an “underperform” rating on the stock and a 12-month price target of $26.

As 2018 heads toward the home stretch, Viacom is among the media companies whose future is soon to be determined. After the dramatic end this month to its litigation with CBS due to the ouster of Les Moonves, the question of management has been settled for now. The consensus view is that it will soon rejoin its former corporate sibling under the same roof, or else seek some other M&A transaction after 12 years of going it alone and seeing peers like Time Warner, Fox and Disney do massive deals.

Juenger’s argument, which he has articulated in some previous research noted, has two main pillars. The first is that Viacom’s “stuffing” of the airwaves with ads contradicts the company’s promises to trim its overall ad load and invites disaster at a moment when viewers already are tuning out live, ad-supported fare. The other part is that it devalues inventory for advertisers at a delicate time in the ad business when they are comparing linear buys with digital campaigns and the tech giants continue to emphasize their ad capabilities.

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“We find this behavior ironic as it relates to Viacom’s claims to be a leader in using analytics to

deliver improved ad efficiency/effectiveness,” Juenger wrote. “The vast majority of inventory is still linear. How effective can an advertising message be, regardless of the analytics behind it, when delivered in such a cluttered, diluted environment, with obviously un-engaged viewers?”

The impact of the maneuvers on Viacom’s ad revenue is unclear, Juenger concedes. But his report reads like a call to arms, urging investors to take a closer look at the company.

“Viacom must be making the calculus that the short-term ability to recognize revenue is more important than the harm,” he wrote. “We think it’s important for investors to decide whether they agree.”