Last month, “The O’Reilly Factor” was typically home to at least 30 nationally broadcast commercials a night. By April 11, the final time Bill O’Reilly hosted the 8 p.m. show on Fox News, that number had dwindled to 10.
The advertising exodus, which followed a report by The New York Times disclosing that five women had received settlements over accusations of inappropriate behavior by Mr. O’Reilly, rattled the network.
While the financial fallout may not have been dire, given that many advertisers shifted their spending to other programs on the network, it was difficult to ignore the image of at least 50 major brands — like Mercedes-Benz and Allstate — declining to associate with Fox News’s most popular personality. Now that Mr. O’Reilly is gone, dismissed on Wednesday by 21st Century Fox, the network’s parent company, the question is: Will the advertising situation on Fox News return to normal?
Mr. O’Reilly, who has denied the allegations against him, will be succeeded in the 8 p.m. Eastern slot by Tucker Carlson, who had been the host at 9 p.m. The round-table show “The Five” will move to 9 p.m. and Sean Hannity will stay as the 10 p.m. host.
Mark Young, chief executive of an ad agency called Jekyll & Hyde, works with several brands that advertise on Fox News, including Australian Dream, a pain relief cream that recently ran commercials on Mr. O’Reilly’s show even after others had begun to boycott it. Mr. Young said on Wednesday evening that Fox News had not contacted him to discuss any changes to its lineup, nor did it say anything when the host Megyn Kelly recently left the network, adding, “Most networks play this kind of thing down and just operate as business as usual.”
Mr. Young also said the companies he worked with bought time blocks rather than time during specific shows. Australian Dream advertises on all the cable networks and aims “not to make any political statement but to reach as many people as possible,” he said.
“At no time did we make a decision to remain on O’Reilly, we made a decision to remain on Fox News,” he said in an email. “It was in the best interest of the client that we continue to reach the valuable audience that Fox News provides us. We will of course be watching the audience numbers and will make future decisions based on the value provided to our client.”
Brian Wieser, an analyst at Pivotal Research, said that Fox News probably recognized that a replacement would cost less than Mr. O’Reilly and still retain most viewers.
“The growth of the network in general overwhelms his rise,” Mr. Wieser said. “If they literally went dark for that hour they would still be ahead, year over year.”
The show generated more than $446 million in ad revenue from 2014 through 2016, and had an average of 33 commercials a night in the month before the revelation about the multiple settlements involving Mr. O’Reilly, according to the research firm Kantar Media. The number of ads excluded local buys and Fox News promotions.
Even if advertisers stuck by Mr. O’Reilly, Mr. Wieser added, the situation raised other questions. “Is it harder to attract talent at Fox because of O’Reilly’s presence or is it harder to book on-air guests?” he asked. “Or is morale so low such that people are unproductive because they feel there’s a risk that’s looming?”
The amount of paid advertising time on weeknight prime-time showings of “The O’Reilly Factor” dropped by more than 50 percent after The Times first reported that the company and Mr. O’Reilly reached settlements with five women who had complained about sexual harassment or other inappropriate behavior by him, according to data from Kantar.
Its advertising last week was dominated by small-budget brands and direct-response marketers like MyPillow.com and a maker of freeze dryers named Harvest Right, the data showed.
On Wednesday, several major companies that had halted their ads from running on the show were not yet sure about whether they would return to the time slot.
“Nothing has changed at this point — we pulled our ads from ‘O’Reilly Factor’ for the indefinite future,” Donna Boland, the manager of corporate communications for Mercedes-Benz, said in an email. “The ads have been reassigned to other Fox News segments.”
T. Rowe Price, the financial firm, said it may be too soon to speculate on where it will buy TV ads in the future, as it makes those purchases only during certain times of the year. This month, the firm pulled planned ads from the show, saying it regularly evaluated its media buys “to ensure alignment with our corporate values.”
Several activist groups that have been using social media to pressure advertisers into pulling their dollars from “The O’Reilly Factor” celebrated the news of Mr. O’Reilly’s departure. One leader of that effort was a Twitter account called Sleeping Giants, which was created in November to pressure brands into removing ads that appear on Breitbart News, the conservative news and opinion website with close ties to the Trump administration. The anonymously run account extended its mission this month, urging advertisers to pull sponsorship from Mr. O’Reilly’s show.
“Thanks to all of the Giants, the many collaborators and the advertisers who stood up to sexual harassment,” the group posted to Twitter on Wednesday. “You did this.”