Sites such as Facebook, Twitter, and LinkedIn, can all be represented using a connection graph:
- Facebook is an undirected graph modeling friendship.
- LinkedIn is also an undirected graph representing professional contacts.
- Twitter is a directed graph (you may follow someone who is not following you, and vice versa).
All of these social media sites include something like a People you may know section. These recommendations can be based on different factors. For instance, they can use the following facts:
- You attended the same university lecture, so you may know each other even if this relationship is not made official on social media.
- You have friends in common, so you are likely either to know each other or to be introduced in the future, at a party, wedding, or other event involving your common friend.
As well as connection recommendations, link prediction can also be used for product recommendations.
