INSTAGRAM tracks the amount of time you spend looking at people’s posts – to help rank your photo feed better.

It means that if you spend a lot of time gawping at a particular person’s saucy snaps, you’re more likely to see posts from them in the future, The Sun can reveal.

It’s all thanks to Instagram’s ranking algorithm, which helps decide which posts to prioritise in your main feed.

When Instagram launched back in 2010, photos and videos were shown in “reverse chronological” order – so you’d always see the latest posts.

But in July 2016, Instagram binned that system for an algorithm that ranked posts based on how likely you were to enjoy them.

This feed order is affected by lots of different factors – including how much time you spend looking at a person’s posts.

Speaking to The Sun, an Instagram spokesperson said: “Because it’s powered by machine learning, Instagram’s feed ranking is constantly adapting and improving based on new data.

“In some cases, the time someone spends looking at another account’s content can be one of the many factors that inform the ranking of posts in their feed.”

We also spoke to Instagram’s Julian Gutman – who heads up the “feed” – about this phenomenon.

He told The Sun: “I think generally you can think about it as different ways you might express your intent in terms of how much that person matters to you, and that’s sort of how we we look at it both across Instagram and Facebook.
“We kind of learn over time which signals are more important than others.”

This, of course, could create a cyclical effect.

The more you look at someone’s photos, the more you’ll see them in your feed – prompting you to look at that person even more.

It could mean a person’s eye-catching snaps turn you into an accidental Instagram stalker.

Yesterday, The Sun revealed how your activity on Facebook affects your Instagram feed order.

That means if you interact with Facebook friends – through likes or comments – regularly, they may appear higher in your Instagram feed.

According to Instagram, lots of different factors affect the ranking system.

But the three primary influencers are your own interests, the timeliness of posts, and your relationship with the poster.

During a recent briefing with journalists, Instagram’s Jill Nussman defended the algorithm.

She argued that a chronological feed “didn’t make sense – it wasn’t serving our community”.

“People were missing 70% of the content in their feed,” she explained.

“Over half of that content was ‘friends and family’ posts.”

According to Jill, the ranking system makes sure you “don’t miss posts that are important to you”.

What would you like to change about Instagram? Let us know in the comments!