Microsoft has many business models and one of them is based on advertisements, example : LinkedIn.
LinkedIn make bank from selling Sales Navigator. Ads are a tiny proportion of their revenue.
Having managed ad campaigns on LinkedIn, that's both surprising and not. They have a horrifically high cost per click compared to other channels, but the results in B2B verticals were usually enough to warrant putting up with it. So it's surprising it was only pulling in around $100mm. But then, their self-service component didn't allow for accessing all of their inventory, and none of my clients wanted to go in with the commitments necessary for the high-touch placements. So that may have dampened demand a good bit.
That said, Sales Navigator (and premium subscriptions) is an equally small portion of revenue. 65% of their money came from their "talent solutions" recruiting features.
[1] https://www.investopedia.com/ask/answers/120214/how-does-lin...
[2] https://www.mediapost.com/publications/article/313837/micros...