"After a thorough and careful review of the allegations, the Company and Bill O'Reilly have agreed that Bill O'Reilly will not be returning to the Fox News Channel," a statement read.

The news is not a complete surprise, but it is nonetheless stunning. O'Reilly, 67, has been hosting the network's 8 p.m. program The O'Reilly Factor for two decades. And it has been the No. 1 show in cable news for 15 consecutive years bringing in more than $400 million in ad revenue between 2014 and 2016 and $118 million in the first three quarters of 2016, according to Kantar Media.

And in recent years, O'Reilly has branched out with a series of best-selling books and spin-off TV movies on National Geographic Channel (majority owned by 21st Century Fox), which have broadened his brand outside of Fox News, where he earns about $18 million annually. 

By the time O'Reilly signed off on April 11 for a pre-planned two-week vacation, the advertiser exodus - including blue chip brands Mercedes-Benz, Allstate, BMW, Bayer and Lexus - had reached more than 50. Many buyers were re-allocating their ad dollars to other Fox News programs. There was also external pressure from advocacy and women's groups including Color of Change and the National Organization for Women.