Facebook is working to persuade advertisers to abandon their boycott. So far, they aren’t impressed.

Facebook has spent the past few days in round-the-clock conversations with advertisers, trying to persuade them to come back to the platform with the promise of modest changes to address concerns that the social network profits from hate and outrage.

But advertisers and the agencies they work with say they are still negotiating. And they say they are so far unimpressed with promises to better police hate speech, including labeling some politicians’ posts when they break the company’s policies. On Tuesday, when the civil rights groups that organized the efforts expect to sit down with chief executive Mark Zuckerberg, they plan to push for changes, including adding a C-suite-level executive dedicated to ensuring that the company’s policies don’t contribute to racism and radicalization.

More than 750 companies, including Coca-Cola, Hershey, and Unilever, have already temporarily paused their advertising on Facebook and its subsidiary Instagram. More companies have joined the movement every day, with recent additions including Walgreens, Best Buy, Ford, and Adidas. More than 200 advertisers joined between Thursday and Friday.

Kerri Pollard, senior vice president of the membership platform Patreon, which is pulling all of its ads from Facebook and Instagram, said that the recent string of concessions still did little to address the company’s core concern: Zuckerberg’s characterization of free speech. The Facebook CEO has said he believes that social platforms should not fact-check politicians.

‘‘Until he softens that, which would affect that entire business internally and externally, we’re not going to feel comfortable returning to the platform,’’ Pollard said.

But fact-checking politicians could have wide-ranging consequences, too. Facebook’s business model depends on engagement: The more time people spend viewing content on the platform, and the more they click and interact with others, the more they are exposed to advertising in Facebook’s scrolling news feed. Critics have argued that divisive and emotional content spreads more rapidly, particularly in like-minded private Facebook groups. That outrage is built into Facebook’s ability to profit.

The boycott is the largest flare-up in a long-simmering battle between advertisers and social platforms over who gets to control what content the ads pop up next to. The campaign, which was triggered by Facebook’s allowing content that organizers said could incite violence against protesters, represents the most substantive effort to date to sanction the social network, which commands the second-largest share of the US digital ad market behind Google.

Facebook spokeswoman Ruchika Budhraja said in a statement that it invests billions every year to keep users safe and works with outside experts to update its policies.

‘‘We’ve opened ourselves up to a civil rights audit, and we have banned 250 white supremacist organizations from Facebook and Instagram,’’ she said. ‘‘We know we have more work to do, and we’ll continue to work with civil rights groups, [the Global Alliance for Responsible Media], and other experts to develop even more tools, technology, and policies to continue this fight.’’

The company has 8 million advertisers, which generated almost all of its approximately $70 billion in ad revenue last year. Most are small businesses.

‘‘Given Facebook’s colossal scandals and rare repercussions to revenue, the advertisers’ boycott is a body blow that will decimate Facebook’s top line. I expect to see a revenue bleed-out of more than $7.5 billion in 2020,’’ said Eric Schiffer, chairman of the Patriarch Organization and Reputation Management Consultants.