Invitation process: @Pair asks you to record a short video to get your significant other to join the service. I a time that is all about social, I enjoy seeing something other than email or Twitter invitations. 

Social invites: when @Joingrouper users invite other people, it’s personal. They remind you that a “friend” has invited you along with an avatar and a few accompanying words.

Social: SoundCloud’s (@soundcloud) media player displays comments at a particular moment of the music file making the track social.