Last April, Roberto Forgione noticed that someone who had ghosted him was looking at his Instagram Stories — the brief, casual updates that hang around for 24 hours at the top of the app’s screen and include lists of the people who have seen them.

“After a couple, I was like, ‘He’s back,’” Forgione, 31, a photo producer in Brooklyn, said. He decided to take a chance and reach out in his direct messages. “I asked him if he wanted to hang out, and he said yes,” Forgione said. The two have continued seeing each other since, spending Thanksgiving together and attending a wedding as each other’s dates.

Anthea Fisher, 22, a project manager in finance, began a relationship on Instagram with someone she had known peripherally. “We liked each other’s stuff from time to time,” she said. “After my ex-boyfriend and I broke up, he started liking a lot of my stuff and watching all of my Stories. He would DM me, he would send me memes. And I sort of knew he was trying to get my attention.”

As of September, Instagram has more than 800 million users worldwide who engage with the app at least once a month. Of those, 300 million use Instagram Stories every day, according to a spokesperson for the company. Some of them use Instagram for their businesses; some for sharing photos of their kids; and some for distributing memes about hungover mornings and overeating. And then there are those who use Instagram as a supplemental match-making tool. “It’s basically a portfolio for your dating life,” said Halen Yau, 31, a public relations manager from Toronto.

Not only does Instagram provide a visually driven collage of your life, it also offers a subtle way of expressing interest through likes and comments, and connecting in the form of a private chat. Meanwhile, the lists of users who have looked at each of your Story cards mean that you now have data — rudimentary and inconclusive, but still, data! — on who exactly is obsessing over you today, tomorrow and yesterday.

>> Confused by the order of story views? Don’t worry. So is everyone else.

“The theory is that whoever are your biggest stalkers on Instagram are at the top,” Fisher said, referring to the lists of users who have looked at your Story. But that is just a theory. According to a spokesperson, the order is “based on a number of signals including people who recently viewed your story, accounts you interact with the most on Instagram, and more.”

The mystery has spawned endless ideas about the ranking of handles. In a thread on Reddit, users have documented experiments in which they altered various factors like how often they looked at a friend’s profile, or how often they liked photos on a profile, to see which ones had an effect on the order and which ones did not. The goal for many was to figure out that all-consuming question: Does my crush like me as much as I like them?

Their experiments yielded mixed results, and Instagram will likely keep the algorithm under lock and key until the end of time. So, if you want to gauge interest anytime soon, we recommend a tried-and-true thermometer: the thirst trap.

>> Thirst traps: what they are and how to use them

Thirst: a strong desire for something; a lust for attention.

Thirst trap: An image or video that’s intended to attract attention from someone and elicit a response.

“A thirst trap can be as simple as a selfie,” said Andrew Keller, 25, a creative strategist at Paper magazine. “I can put up a really cute selfie of me, and the caption can be, ‘Just ate a bag of Twizzlers, hate myself.’”

“It’s like you’re throwing out a net into a sea of fish,” Yau said. “Whenever I post a story, I kind of have an idea already of who will respond or what kind of response I will get.” If you are successful, the person you are targeting will be tempted to comment. Might even actually comment. Might even “slide into your DMs.” If so, you have pulled off your very own thirst trap.

“Everyone has that one person in their mind that they want to see it,” Keller said. Waiting for their response, he said, “can be torture in itself.”

Once you have mastered the thirst trap, advance your skills by making use of the blocking tool. If you want to post something racy for a select few fans of your Stories, you can go into settings and hide the Story from other users. Ta-da! Now Susan from work will, quite fortunately, not see that photo of you perched seductively on her desk after-hours, a bottle of champagne from the holiday party in your hand.

Side note: Sometimes you’ll receive unwanted attention that can cross the line into harassment or bullying. In cases like that, block the user and report them to Instagram.

>> @Romeo and @Juliet sitting in a tree. First come the likes, then come the comments and the DMs.

If you want your Dulcinea to know that you’re categorically interested, you will have to do more than check their Stories and post thirst traps. Attend to their profile page, where you can see all their photos, as well. Paying a compliment on Instagram is as simple as liking a few photos.

“One ‘like’ could be, ‘I randomly liked your stuff,’” Keller said. “Two is, ‘I like two of your photos.’ Three is, ‘I’m intentionally trying to get your attention.’ It’s the equivalent of eyeing someone in a bar.”

“Commenting would be equivalent to walking up to someone and saying a very basic hello,” Keller said. “The DMing is the official, ‘I’m here and I’m not playing around.’” Fisher agreed: “Once they’re in your DMs and they’re commenting on things, that’s when they’re trying to make a move.”

As in real life, reciprocation is important.

“You, of course, have to wait a little bit to see if they like your photos back,” Keller said. “It’s the same as if you’re looking at someone at the club and they’re not looking back.”

Another factor to keep in mind in the era of Insta-fame is how many followers your romantic interest has.

“Anyone above 75,000 is probably not going to notice you if you like their stuff,” Keller said. “If they like your stuff, that’s a different ballgame because it means they went out of their way. Then it’s, ‘Ding, ding, ding.’”

And though Instagram can offer more depth than an abbreviated Tinder or Bumble or Grindr profile, do not forget that it is still a curated highlight reel. “I’ve had guys straight up refuse to believe that I’m me,” said Kris Kidd, 24, a writer and model in Los Angeles with more than 24,000 followers on Instagram. When men meet him IRL, they are surprised to find that his real-life personality is not as exaggerated as his Instagram persona. “It’s a two-dimensional platform, which inherently means we can’t see everything. It would be really unhealthy to show all of ourselves on social media.”

Adjust your expectations accordingly.

>> How to survive the wasteland that is post-breakup Instagram

Unfortunately, Instagram is not all romance and daisies. In some cases, rather than serving as a conduit for an attraction, Instagram is a reminder of what is gone.

When Forgione began dating his current flame, his ex-boyfriend started paying a lot of attention to his Stories and his feed. “The level of him creeping on me was out of control, to the point that he texted asking me, ‘Who is your new boyfriend?’” he said. “The guy I’m seeing has posted things about me and just from him doing that and tagging me, I’ve seen on my Stories guys who follow him looking at my stuff,” he said. “People are creeping on him and then creeping on me.”

Not that Forgione is above checking up on his exes.

“After an ex and I broke up, of course I was crazy stalking him,” he said. But, he added, “I didn’t want him to see that I was looking at his videos.” So he used a co-worker’s fake Instagram account to see what his ex was up to.

And he is not alone.

“I add a guy on my fake account even before we break up,” Yau said. “As soon as I know things are going south, I’ll add him. I have a fake account that all my exes are on. And I have two exes watching my Stories on their fake accounts.”

Why look?

“I delete them (from my main account) to make a statement: ‘I don’t want to keep up with your life anymore,’” Yau said. “But I believe that knowledge is power, even if it makes me feel crappy, I still want to know.”

“The only person you want to be in that much pain with when you’re breaking up is the person you’re breaking up with, so maybe there’s some impetus to look at their page to gauge how they’re doing and look for some sign that they’re also feeling bad,” said Leora Trub, an assistant professor of psychology at Pace University and a clinical psychologist.

Michel Kobbi, 27, a marketing manager from Montreal, offered a more positive take.

“Seeing the new life in pictures helps bring a certain closure,” Kobbi said. “Then I know I’m totally fine with the relationship ending and I think it ends with another layer of healthiness to it. It’s really turning the page for both people.”

Other social media platforms have had similar effects, but Instagram is massive (just Stories has nearly twice as many users as Snapchat does), and other pervasive platforms, such as Facebook, are not as dominated by daily, visual updates. Nor, frankly, are they considered as cool as Instagram.

“I obviously have Facebook, but I rarely, rarely use it,” Forgione said. “Your grandmother’s on it.”

As with real-life breakups, each person will have a unique experience.

“How we interpret it is totally idiosyncratic,” Keller said. “It could be, ‘They’re having such a great time’ or ‘They must be really compensating for how sad they are.’”

“People are giving themselves just enough information to come to conclusions about how that person doing that have more to do with how they’re perceiving how that person is doing rather than how they’re actually doing,” Trub said.

And therein lies the final lesson: Instagram is a window, but also a facade.

“The truth is you can’t look at someone’s Instagram account and know how they’re feeling,” Trub said.