[underwater]

The original assertion that advertising and data sharing are equivalent. But even in your examples the information is still fire-walled.

Google can know that you're expecting, because of a congratulation email. Facebook can know you're expecting, because of a life event. Arbitrary companies can't know who their baby store ad is being shown to.

You can argue that Google and Facebook are too big, and data being shared between YouTube, Gmail, Google Adwords, etc. is suboptimal. But that's still better than a company that will freely sell a database of information to be resold, mixed, etc. forevermore.