What dematerialization? Facebook's entire business model is advertising, in other words: getting you to buy things. It used to be Google's and Amazon's entire business model, too, until they diversified into cloud services.
It's the exact opposite of dematerialization.
Edit: To clarify, I'm not at all against these things. On the contrary. My point is that among those people most vocal in demanding (sometimes radical) change from others, I frequently see a complete lack of self-reflection.
It doesn't really matter whether the people calling for radical change are hypocrites or not. That has no material affect on whether there really is a need for radical change. It does make them rather annoying and gives those resistant to change something to criticise them over but it doesn't alter the facts of the situation.
It affects the discussion of the situation and, by extension, the politics surrounding it, and thereby ultimately the one force that might actually effect the necessary change.
E-mail reduced the amount of letters, but Amazon increased the amount of packages.
Over-the-air TV broadcasts consumed way less energy than FHD personalized YouTube streams.
Americans own more than 20 electronic products per household.
etc.