The Deal: PayPal is building an ad network powered by its massive user base (around 400 million) and their shopping habits. This means personalized promotions and targeted ads based on your purchase history.

Why It Matters:

Key Players:

Current State:

Industry Context:  

This follows a trend of financial giants (like JPMorgan Chase) leveraging customer data for ad revenue.

Overall:  This move could revolutionize targeted advertising based on real purchasing habits.  Expect more personalized promotions and ads popping up across the web (with the option to opt-out if you prefer).