I think the author makes a very good point.
"the fact that offering free, advertising-supported services to millions upon millions of people is not a lean and- mean undertaking"
and
"They figured that the revenue and profits would come eventually but clearly that was putting the cart before the horse"
I see lots of people on HN building great products who have clearly not asked (and answered) the most important question: How will my service make money?
It should be becoming painfully clear that layering advertising on top of a useful service does not work.
Adsense works because it puts relevant ads in front of people who are already searching for something.
FB users are connecting with friends not looking for products.