Sharing: Pair has a built in function that let’s you suggest the app to others. It automatically fetches the name of your partner and points out two other important facts: messaging, free.

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. 

#Pair Giveaway: @Pair is giving away something that its audience will love: 2 iPhones. There’s a lesson there somewhere. Give away something that your target audience would love to have and let them share the news. 

Here’s a screenshot of how they handle the contest.