Now, social media agencies are wondering if the same is on the cards for Instagram. Some claim it is already happening.
The concerns raised this week remind me of the fevered anguish every time Google has tweaked its search algorithm. Chat rooms and forums fill with media executives wondering aloud whether it's just them seeing unusual results.
There are, apparently, a lot of social media marketing executives out there currently wondering why some posts are dying an invisible death away from the oxygen of free, organic exposure to audiences.
For now, Instagram is saying it hasn't altered anything -- it's business as usual. Whether this means that no major tweak has officially happened by little bits of tinkering going on is anyone's guess.
What is almost certainly the case is that Instagram is becoming a tougher place to achieve mass organic reach. From what social media execs are saying, it seems that posts have to get a lot of early traction to get wide exposure to users' feeds.
There is also a lot of chatter that making posts shoppable has led to a more crowded market place, as have IGTV, Instagram's answer to YouTube.
It is probably not a coincidence that these concerns have risen to the surface at a time when Instagram has empowered brands to boost influencer posts. We now have shoppable posts and "brand-boostable" influencer campaigns, and that means timelines will become crowded with paid-for posts.
It is all very similar to what has happened with Facebook over the past couple of years. People got angry, but then ultimately accepted that as with any media channel, advertising is always the guaranteed way of getting exposure.
So, if posts need early traction, how are you going to get it? Chances are that more people are going to be tempted to boost. If you want to get particular audiences that you're not quite hitting in enough numbers organically, the answer, again, will increasingly be to pay.
Brands may choose to boost their own posts or influencers, or most likely, a combination of the two.
What is almost certain is that as with Facebook, Instagram is approaching the end of its golden era where marketers could expect wide reach for free. Just as with Facebook, new ways of paying to engage with users are being investigated which can only take the site in one direction.
Like a drug dealer that has got marketers hooked on the pictorial equivalent of catnip, the free "hits" aren't going to be taken away altogether but if you want the good stuff, it's time to release some budget.