The Half-Life of Instagram Posts

Update 30 Aug 2016


Instagram changed feed ranking from a linear time based feed to an algorithm based ranking. So far we have not noticed any statistically significant changes to the engagement activity. On average posts get the same engagement at the same speed.

From Wikipedia:

Half-life (t1⁄2) is the amount of time required for the amount of something to fall to half its initial value. The term is very commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay, but it is also used more generally for discussing any type of exponential decay.

Linear vs. Algorithmic Feeds

As a platform connecting brands and influencers, we’re interested in the laws governing engagement of Instagram posts. Instagram and Twitter famously implement non-symmetric friend relationships, and linear content feeds. Facebook has symmetric relationships, meaning that the primary relationship exists in both directions (i.e. ‘friending’ as opposed to ‘following’). A simple chart denotes the main differences between social networks:

50% of all Instagram post engagement happens in the first hour

An important side-effect of linear feeds like Instagram or Twitter is that the onus of increasing the overall quality of experience is on the user, not an algorithm. By unfollowing lower quality profiles and following higher quality ones, over time the platform experience becomes ever more tailored. The content Facebook decides to display in your feed, and the order in which it gets displayed is affected by a flurry of variables; frequency of engagement, paid placement by advertisers, ‘strength’ of friendship, time of day, engagement rates and even your relationship with the people who have engaged (Your friend liked this photo). Algorithmic platforms detect over time your affinity and potential interest for content (potentially creating more wiggle room for paid distribution of advertorial or sponsored content).

For platforms with linear feeds the user must decide if a profile they follow is of interest or not — instead of the algorithm fading the content slowly out of your social media diet, you must manually unfollow undesired content. This creates a fundamentally different kind of dynamic and tension between creators and consumers of media. Influencers are painfully cognizant of how easily “unfollowed” they are by wrong moves or half baked posts. The acquired followers become more valuable, and their presence is direct.

At the heart of Takumi is tapping into this tension between content creators and their followers.

Another dynamic of linear feeds is the unforgiving burying of posts. The age of a post becomes the key variable to engagement, as posts are displayed in reverse-chronological order the most recent one gets all the attention, and the rest are at the mercy of the users’ willingness to dig deeper and deeper into their feeds.

Just how fast does the engagement accumulate? For users IG content is never pushed or promoted by the platform, so engagement becomes a game of time-optimization and immediate feedback while engagement is accruing.

We looked at our data for Takumi sponsored posts and saw just how quickly Instagram posts gather meaningful statistics.

50% of all Instagram post engagement happens in the first hour
  • 1st hour: 47% of total engagement
  • 2nd hour: 57%
  • 3rd hour: 63%
  • 4th hour: 66%

Instagram Post Half-Life: 1.2 hours
In other words: It takes 72 minutes for an Instagram post to gather half its total engagement.