Microsoft and Google will duke it out over Silicon Valley's true financial driver: ads

• Much of Silicon Valley really runs on money from online ads.
• Google search dominated, but Microsoft's AI-powered Bing is emerging as a credible challenger.
• Microsoft says for every market share point increase in search it gains, it can earn $2 billion.

For all the talk of driverless cars, internet drones, and the metaverse, Silicon Valley's biggest players rely heavily on one source of cash: online ads.