> As a medium for creating and then feeding a minor addiction to clicks of the "like" button in response to photos of my kids, in exchange for "a non-exclusive,

> As a medium for creating and then feeding a minor addiction to clicks of the "like" button in response to photos of my kids, in exchange for "a non-exclusive, transferable, sub-licensable, royalty-free, worldwide license to use" them, on the other hand, it seems to be amazingly well-optimized. Their model appears to be largely based around perpetuating the high-school clic mentality for the purpose of shoving advertising at the clic members in order to profit. The addiction (just as in the high-school clic) is to be a member of the "in" crowd (for whatever definition of "in" applies). Which is probably why there is only "friend" (which clearly fails, as you detail, to capture the nuances of real social interaction). With only a single linking level, each new clic member feels just as important as another, feeding the addiction just a little bit (the "I'm important, because X is friends with me" mindset).