New data suggests a total of 935 companies have pulled advertising away from Breitbart, the pro-Trump enterprise founded by the President's senior aide Stephen Bannon.
Media and advertising watchdog Sleeping Giants has claimed corporations like Lufthansa, Kelloggs, and T-Mobile have severed their connections with the company and its ultra-conservative news website.
The current ban on advertising appears to have stemmed from an incident in February, when Donald Trump threatened to cut funding to the University of California, Berkeley after it cancelled a planned speech by Milo Yiannopoulos.
Yiannopoulos later resigned from Breitbart News after making controversial comments about paedophilia.
Analysts from the campaign claim the latest figures show the ban on advertising is snowballing.
The site, which has been accused of writing racist and misogynstic articles, has long divided opinon, with company founder Stephen Bannon - now Trump's chief strategist - telling US magazine Mother Jones last year "we're the platform for the alt-right."