How much financially is a customer worth to Google? I know its a coarse metric, but in the "Twitter should have paid ad-free Pro accounts!" conversations, peop

How much financially is a customer worth to Google? I know its a coarse metric, but in the "Twitter should have paid ad-free Pro accounts!" conversations, people always point out that if you look at Twitter's userbase versus its valuation, customers are worth more to Twitter as advertising eyeballs than customers would be willing to pay to become ad-free subscribers. If that's the case -- if people are actually worth more to the company "for free" -- then the company should take care of those users when they try to leave. I don't know if that metric actually holds water, even in the Twitter examples where it's frequently used, but the point remains that while customers aren't directly paying money for Google services, they are not without value when it comes to Google functioning. Google isn't offering its services to the public as a public service.