Power couples like Jay Z and Beyoncé, Kim and Kanye, and Blake Lively and Ryan Reynolds have been around for as long as Hollywood, and they won't stop fascinating fans anytime soon. But they are now sharing the spotlight with a different kind of celeb relationship: the power BFF.

Just ask Taylor Swift. The release of her new album 1989 is arguably the biggest entertainment news story of the week, and the publicity blitz isn't coming just from her PR team's planned interviews and carefully booked talk show appearances, or from Taylor's own social media feeds. It's also coming from the mouths of Taylor's super famous friends.

First Lena Dunham posted a photo to Instagram of her and Taylor on a beach; then Lena tweeted about it; then Lorde tweeted a picture of her and Taylor on a beach; then both Lena and Lorde tweeted their favorite tracks. And then, deep breath, Lena pointed out the obvious: The two of them must be part of some "cozy cozy cozy-ass cult."

Exactly. Taylor traded high-profile romances for high-profile friendships — and, whether it was calculated or not, it was a brilliant move.

When two stars become close friends and do things normal, non-famous women do together — like Nina Dobrev and Julianne Hough going to a Kings of Leon concert — it makes us, their fans, feel a closer connection to them. Not only can we relate to those scenarios more than we do, say, a famous married couple posing together on a red carpet, but we're more likely to believe them.

"When it's a shot of a boyfriend and girlfriend, fans tend to wonder in the back of their mind if it's a publicity stunt and if they are just acting the part for our benefit," says Meredith Guthrie, Ph.D., professor of media studies at University of Pittsburgh. "We haven't gotten that cynical yet about friendships. When we see a pic of two famous people just hanging out, getting pedicures together or whatever, it feels a lot more real."

But is it? These relationships may be platonic, but they carry a lot of weight when it comes to a star's reputation. It's always been that way with romantic relationships: Start dating someone new in Hollywood and your stock will rise or fall. But now the same thing is happening with friendships. Pick the right bestie and all of a sudden you're cooler than ever; go with a bad girl (like Katy Perry did with Rihanna) and you're given an edge you never had before. "Hanging out with the right celebrity can really help or hurt your profile," says Ben Margherita, former art director at Us Weekly. "If you're Chelsea Handler and you become good friends with A-lister Jennifer Aniston, it elevates you to a whole new level."

Because of the effect a new friendship can have on a celebrity's reputation, the very public displays of friendly affection might not be quite as unscripted as you'd want to believe. By broadcasting friendships through Twitter and Instagram as often as they can, stars can show how accessible and "real" they are. This also allows them to engage with fans without shining a light on whatever is going on with them romantically. It's kind of like a magician telling you to focus on one part of the stage while the real trick is happening on the other side. Cara Delevingne and Selena Gomez go on a cruise together, and all of a sudden we're focused on that instead of whether Selena and Justin are back together again (please, no).

"If a star is broadcasting her friendship by talking about it in interviews, getting photographed together, or interacting on social media, she is absolutely aware of the way it will affect her image," says Anne Helen Peterson, Ph.D., author of Scandals of Classic Hollywood. "I'm not saying that celebrities don't do things that are natural and without agenda, but they tend to keep those things more private."

Instead, they are putting these images out there, knowing full well they are going to spread all over the Internet. There's Nicki Minaj with a laughing Cara Delevingne, Lena Dunham mashing her face into Mindy Kaling, and Jennifer Lopez tweeting at Leah Remini with the hashtag #luckybesties. And then there's the celebrity friendship Instagram to end all celebrity friendship Instagrams: Taylor Swift's 4th of July party shot with Lena Dunham, Emma Stone, Jaime King, and others. There probably wasn't a single entertainment site that didn't blog that image — and there probably wasn't a single celeb in that photo who didn't know that was going to happen.

Even if these relationships are a little strategized, though, you can't deny that the rise of the power BFF has an awesome girl-power vibe to it. This quote from Lorde about T-Swift sums it up perfectly: "It's the coolest thing in the world having friends who make incredible music AND having them cheering you on when it's time for your own to be released."

She might as well be saying, "Who needs a guy to lift you up when you have great friends?" And that's important. "It's tiring to have female stars constantly identified by the man they're dating," says Guthrie. "That's why these friendships are so empowering. Women are forgetting about guys and going out and having fun. And, oh yeah, they are empowering their careers too."

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