Yep - he did that with Instagram and Whatsapp. While I dislike the guy, it is certainly a powerful strategy to retain the top spot in social media networks. Once you have mastered a particular art (in this case running social networks) then you start to become an expert in the real value and can afford to outbid your competitors in that market.
It's really reminiscent of the Rockefellers and AT&T before the government stepped in. Left to their own companies eventually form a monopoly as they grow too big, unless something disruptive they haven't prepared for arises (like how online shopping killed off Sears, etc.)
I dislike him mostly coz of that landgrabbing issue in Hawaii.