One third of AOL's revenue is generated from Google Ads. More dramatic than that number, one half of AOL Media's (AOL's online publishing division) revenue comes from Google Ads. This revenue is high-margin with little direct cost, which makes it highly valuable to the company.
AOL is having quite a challenge trying to move the company in a positive direction. Now, AOL is faced with a new and quite severe challenge--the revenue coming from the Google Ads is shrinking.
From SEC reports, AOL's year over year revenue is down 24%.