Re: The real fun has n't even started yet..
"End of metrics collection experiment."
First, you're using "metrics" in an overly broad sense here. Google purchases this data in order to match up online activity with physical purchase activity. That's a whole lot more than what people tend to think of when they think "metrics".
Second, I don't see anywhere that this effort has ended. I may have missed it, but even the article you linked to doesn't say they've stopped.
Third, it's not just credit card information. Google also has deal to collect Wifi & Bluetooth pings that stores increasingly use to track you. Google has expanded their already overly invasive spying activities into the physical world on several fronts.
I'm not seeing how their behavior is better than Facebook's.