A reservation queue would have worked just as well. (first in first served) The invite system sets up existing hierarchy of insiders and outsiders from the get-

A reservation queue would have worked just as well. (first in first served) The invite system sets up existing hierarchy of insiders and outsiders from the get-go, favoring the already popular, and creating a wall for new (single) users perhaps not in the hot geolocations where invites get handed out in bulk. It actually excludes people who are already struggling to socialize, and rewards those who have all the 'right connections'.