Social proof is just network effect. Could be called marketing 2.0 the online and offline community
What is social proof? Put simply, it’s the positive influence created when someone finds out that others are doing something. It’s also known as informational social influence.
Consider the social proof of a line of people standing behind a velvet rope, waiting to get into a club. The line makes most people walking by want to find out what’s worth the wait. The digital equivalent of the velvet rope helped build viral growth for initially invite-only launches like Gmail, Gilt Groupe, Spotify, and Turntable.fm.
The social proof message – “Almost 75% of other guests help by using their towels more than once” had 25% better results than all other messages. And adding the words “of other guests that stayed in this room” had even more impact (also an example of how A/B testing of small details matters).
In another study, a restaurant increased sales of specific dishes by 13-20% just by highlighting them as “our most popular items”. SP also works on your subconscious – it’s the reason why comedy shows often use a laugh track or audience; people actually laugh more when they can hear other people laughing.