I want to add to what Braiam has said. Stack Exchange has the following badges as reward for sharing a link with your networks: 

 1. [Announcer][]:  
   *Shared a link to a question that was visited by 25 unique IP addresses.*
 2. [Booster][]:  
   *Shared a link to a question that was visited by 300 unique IP addresses.*
 3. [Publicist][]:  
   *Shared a link to a question that was visited by 1000 unique IP addresses.*

If you are after more information those badges are specified on the [badges](http://askubuntu.com/help/badges) section.

[Announcer]: http://askubuntu.com/help/badges/57/announcer
[Booster]:   http://askubuntu.com/help/badges/58/booster
[Publicist]: http://askubuntu.com/help/badges/59/publicist