The line between Instagram and Facebook is getting very, very thin—and here's why you should care

An algorithmic feed. Live video. A seemingly unquenchable thirst to copy Snapchat. Sound like an app you know? You'd be forgiven for thinking the answer was Facebook, though, it's not.

Instagram's the app you're looking for, and it's been steadily moving closer to Facebook (which owns Instagram) in recent months.

And on Tuesday, the company took the next step in that direction, and announced it was adding the ability to "like" comments within posts.

While Instagram CEO Kevin Systrom billed it as a way to "encourage positivity" on the platform, for many, the move's just the latest in a series of ways Instagram is more and more often resembling Facebook.

On the surface, being able to "like" comments may seem like a small change, but it's one that highlights just how much the company has moved away from its photo-first origins in the last six months.

That's troubling to many longtime Instagram users attracted to the app precisely because it was so different from Facebook.

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Historically, Instagram has always been more about capturing a moment—and making beautiful photos—more than sharing everything you do that day, or having long-ranging discussions in a comments thread. Now, that era's over. Sure, there are still plenty of well-composed photos and cute cat videos and #tbt posts to be found, but increasingly, that type of material is becoming a sole component in Instagram's bucket, which is being increasingly filled with other features, built on other platforms.

By putting a stronger emphasis on commenting, Instagram's doing more than signaling its desire for users to engage each other more. It's also opening the door for other updates within the field of commenting—like ranked comments, which could place comments with more likes at the top of a thread (Instagram says it doesn't have plans to do this yet, but the feature could easily be implemented in a later update).

Consider some of Instagram's most recent updates, which have also been some of the app's most significant changes yet.

• June 2016: Instagram's long-rumored algorithmic timeline, which orders posts based on "what you care about" rather than chronology, finally rolls out. Users react badly.

• August 2016: In a bid to compete with Snapchat, Instagram launches Stories, which is essentially a copy of the Snapchat feature of the same name. Users, once again, say they hate it.

• November 2016: Live video comes to Instagram with a twist: ephemerality, meaning they disappear as soon as the broadcast is over. The app also adds ephemeral messaging to Instagram Direct.

• December 2016: Instagram comments get the Facebook treatment.

Taken together, it's clear Instagram's making a concerted effort to make its network more like Facebook. Each of these is a very carefully designed feature to keep you in Instagram app for longer periods of time, and encourage the variants of conversation and sharing more often found on Facebook than Instagram.

Why? To boost engagement, of course. Though the app's growth has been fairly insane, given that it's only been around for six years (and passed the 500 million user mark this year), it still has significantly fewer users than Facebook or WhatsApp. And its engagement is smaller still when compared to other Facebook apps.

Consider: of 500 million monthly Instagram users, more than 300 million of them use the app daily, according to stats the company announced in June prior to the launch of Stories. An even smaller percentage of those 300 million users post to Instagram each day. The app sees, on average, "more than 95 million" photo and video posts a day, the company said at the time.

Put another way? At best, less than one-third of the app's daily users were posting each day, prior to the launch of Stories. That starts to look pretty paltry when put up against Facebook or WhatsApp's or even Messenger's stats.

Fast-forward to just a few months after the launch of Stories, though, and the company says more than 100 million people use the feature daily.

In other words: Stories has been a boon for Instagram, and the company is likely hoping for similar success with live video and ephemeral messaging and comments.

The fact that some users see those features as ripoffs from other services is less important than how much they actually get used. So, as long as these features continue to produce positive results, expect even more Facebook-like features from Instagram.

But the further Instagram moves away from its roots, the riskier this strategy becomes. As the app gets more like Facebook, it risks losing the photos-first focus that made it a success in the first place. And as it adds more and more features separate from its core photo and video posts, it becomes more indistinguishable from other services like Snapchat.

The new features are certainly opening doors for Instagram's continued growth, but as it pushes forward, Instagram also now needs to watch its back and its blind spots, lest another app rush to fill the gaps it's leaving in Instagram's march towards social media homogeneity. After all, that's how a great disruptor—like Instagram once was to Facebook—always starts.