Facebook’s chat sidebar allows users to see which of their friends are currently online and available to chat. The sidebar shows a subset of a user’s friends list, rather than all friends at once. This raises the question: how does Facebook determine which friends to display in the chat sidebar?
Factors That Influence Chat Sidebar
There are a few key factors that influence which friends Facebook shows you in the chat sidebar:
- Recency of interaction – Friends you’ve interacted with more recently (messages, likes, comments, etc) are more likely to be displayed.
- Frequency of interaction – Friends you interact with often are given priority over friends you rarely interact with.
- Closeness of relationship – Facebook may analyze your patterns of interaction to determine your “closest” friends and prioritize displaying them.
- Active status – Friends who are currently active on Facebook are more likely to be displayed than inactive friends.
- Number of mutual friends – Friends who share more mutual connections with you may be deemed more relevant.
So in summary, the chat sidebar algorithm favors friends you engage with regularly, those with stronger relationship ties to you, and those currently active on Facebook.
Ranking Algorithm
Facebook uses a complex proprietary algorithm to rank and select which friends appear in the chat sidebar. While the exact details of the algorithm are not publicly known, we can make some educated guesses as to how it works:
Each of a user’s friends is likely assigned a score based on the factors mentioned above. Facebook’s algorithm analyzes the user’s interactions, connections, and activity patterns to determine a relevance score for each friend.
The algorithm may also assign different weights to certain factors. For example, recency of interaction may be weighted more heavily than number of mutual friends.
Facebook then ranks the user’s friends in descending order by their relevance score. Friends with the highest scores are selected to be displayed in the chat sidebar, up to a certain limit (around 20 friends).
The ranked list is re-sorted in real-time as scores change. When a user interacts with a friend, it boosts their relevance score, making them more likely to appear in the sidebar. Similarly, prolonged inactivity from a friend may cause their score to drop.
In summary, the chat sidebar algorithm is constantly evaluating the user’s friendship network and interactions to serve up the most relevant friends for messaging.
Custom Controls
While the algorithm decides which friends are shown by default, users do have some custom controls:
- Pinning – Users can “pin” specific friends to the top of their chat list to ensure constant visibility.
- Hiding – Users can hide friends from appearing in the sidebar, even when active.
- Grouping – Users can create custom friend lists to group specific friends together.
Using these controls overrides the ranking algorithm and gives users more say over their chat sidebar. Pinning essentially acts as a persistent boost to a friend’s relevance score.
Limitations
Some limitations of Facebook’s approach include:
- Lack of transparency – The proprietary nature of the algorithm makes it difficult for users to know exactly why some friends are shown over others.
- Prioritizing existing relationships – By emphasizing current interaction patterns, newer friends or those trying to reconnect have a harder time surfacing in the sidebar.
- Filter bubble – Some critics argue the highly-personalized sidebar contributes to filter bubbles by limiting exposure to a narrow subset of your network.
- Difficult to deactivate – Even if a user hides a friend, the ranking algorithm may surface them again later if their score increases.
Ads and Sponsored Friends
In addition to the user’s organic friend network, Facebook may also insert sponsored friends and ads into the chat sidebar:
- Pages – Public figures, artists, brands, or businesses can pay to get their Facebook Page inserted into a user’s chat list.
- Click-to-Message Ads – Businesses can buy ads that allow users to start a Messenger conversation.
- Friend Recommendations – Facebook may suggest “People You May Know” based on connections, contacts, etc. These are organic, but can feel like ads.
These paid organic placements allow brands, celebrities, and new connections to increase their visibility and get on a user’s chat radar.
Users can hide any unwanted sponsored friends just like regular friends. However, Facebook’s need to monetize does present a trade-off between relevance and revenue.
Conclusion
Facebook uses a personalized, dynamic algorithm to determine which friends are shown in the Messenger sidebar. Factors like interaction recency, relationship strength, and active status influence each friend’s relevance score. The top-scoring, most relevant friends surface in the sidebar, with some slots reserved for sponsored placements.
While not perfect, Facebook’s approach represents an attempt to balance relevance, user controls, and business objectives. The chat sidebar joins a long list of personalized Facebook feeds designed to connect users with the content, friends, and accounts most likely to resonate with them in real-time.