But this year, the fake follower economy has started to crumble.

In late January, New York attorney general Eric T. Schneiderman announced that he was opening an investigation into Devumi, a seller of fake followers whose shenanigans were detailed in a New York Times exposé.

In July, Twitter purged tens of millions of likely fake accounts, a move that cost some of its most popular individual users more than a million of their followers.

Now, Instagram is taking action too. Yesterday, in a blog post entitled Reducing Inauthentic Activity on Instagram, the Facebook-owned service announced that it is going to be taking action to reign in fake likes, follows and comments.

Here’s what brands need to know about Instagram’s crackdown.

Third-party apps are the focus

Much of the inauthentic activity on Instagram is generated by the use of third-party apps. When Instagram users grant these apps access to their accounts, they can like, comment and follow on their behalf.

In some cases, users don’t know that they are granting apps this kind of access, or are duped into granting access.

According to Instagram, “accounts we identify using these services will receive an in-app message alerting them that we have removed the inauthentic likes, follows and comments given by their account to others. We will also ask them to secure their account by changing their password.”

Instagram says that it will be monitoring activity regularly and accounts that continue to use third-party apps that violate its policies “may see their Instagram experience impacted.” Instagram did not provide more detail about punishment, or whether it would go so far as to remove accounts.

Instagram’s approach doesn’t appear to be a panacea

By targeting third-party apps, Instagram might be able to meaningfully reduce certain kinds of abuse. For example, some Instagram users use third-party apps to automatically follow and then later unfollow other users.

The rationale: some percentage of the users followed will follow them back. By unfollowing accounts later, it’s possible for users to create the appearance that their accounts have impressive followers-to-following ratios.

But this is just one kind of abuse. Instagram users willing to spend money don’t have to use such third-party apps to game the system; they can simply buy fake followers, likes and comments.

While it might be more difficult for sellers of fake followers and engagement to operate if Instagram’s new system works, users who purchase fake followers and engagement without the use of third-party apps will still ostensibly be more difficult for Instagram to punish, because it’s often near-impossible to determine whether the fake followers and engagement were purchased by the user themselves or not.

This is especially true for the most popular of accounts, which are naturally more likely to be followed by fake accounts anyway.

Brands still need to do due diligence when dealing with influencers

Because Instagram is seemingly limited in just how much it can do, especially as it relates to punishing those who don’t use third-party apps but rather buy fake followers and engagement, brands would be ill-advised to assume that these are soon to be a thing of the past.

As Instagram itself noted in its blog post, “since the early days of Instagram, we have auto-detected and removed fake accounts to protect our community” – yet fake accounts are still present on the platform.

This highlights an inconvenient truth: no matter how hard social media companies work to reign in abuse, the significant demand for fake followers and engagement means that they will realistically always be locked in an arm’s race with bad actors who stand to profit handsomely by meeting that demand.

For brands, some of which are now paying tens of thousands of dollars or more to have prominent influencers feature them in their posts, Instagram’s move should change very little for the time being. They should still seek to thoroughly vet the influencers they work with, both quantitatively and qualitatively, and make sure that they are set up to track meaningful metrics, such as sales, associated with their influencer campaigns.