Media Matters:

How much has the advertising exodus cost Fox News? In September 2009, ColorForChange, which was instrumental in launching the Beck ad boycott, published its analysis. Based on advertising rates it concluded that Glenn Beck was bringing in approximately $600,000 less per-week (or approximately $2.4 million per-month), than it was before the boycott began. Keep in mind, that’s when 50 or 60 advertisers had jumped ship. Today, that number hovers between 300-400.

Using that $2.4 million per month estimate, since the fall of 2009, it’s possible the ad-starved Beck show booked nearly $43 million less than it would have if it weren’t facing a boycott. $43 million.