[LaurentS]

I actually wonder about this. SO's typical user is tech-savvy, and I would imagine many access the site with adblockers on (I do). So I suspect my value to the site in terms of ads is close to zero. I would happily pay a monthly subscription to know that the service will remain, given how much value I derive from it, if that gave me the assurance that they won't track me with ads/cookies/fingerprinting.

Their other income is from job ads, and I guess the value is that they have lots of data points about their logged in users (with scores high enough to imply they've interacted with the site a fair bit), in the form of what is posted, worth more than the aggregated list of websites that a user sees (as reported by ads).

I'd love to know more about this, as I have very little understanding of the economics of serving targeted ads. How much can they be making from ads?