Ms. Mayer with Team Stamped (Photo: Instagram)

This is about as close as Marissa Mayer has come to being featured in an episode of Entourage. Today, word leaked that the new Yahoo CEO made her first acquisition--or acqui-hire, depending on who you ask. Ms. Mayer has purchased Stamped, a New York City-based recommendations app cofounded by two fellow Xooglers. Stamped cofounder Robby Stein worked closely with Ms. Mayer when the two were both still employed by GOOG.

Mashable says Stamped's team, five of whom are former Google employees, will be joining "a new mobile product team to be established in New York under the leadership of Stamped’s three co-founders." In a blog post published to the Stamped site, the team confirmed that they will be "discontinuing the Stamped product" but are working on a solution for users to export their data from the app.

Business Insider reports that the deal was closed for a ''a nice size," but nothing too hefty. That should mean some extra spending money for a group of people who have no need for it: Stamped's celebrity investors.

Back in July, when Stamped decided to pivot from a ratings app into a recommendations app--the company brought on a slew of celebrity investors like Justin Bieber, his manager Scooter Braun, Ellen Degeneres, and Ryan Seacrest--alongside established players like Bain Capital Ventures, Google Ventures, Metamorphic Ventures. (Stamped wasn't the only startup to give up on trying to rate things: Kevin Rose's Oink shut down in March.)

Stamped is bright, sleek-looking, and easy-to-use, but around the time of the revamp, we wondered whether it would be able to get any traction in recommendations--even with Biebs filming videos about his favorite things. The gamble may not have worked as intended. Mashable notes both the iPhone and web app will be "discontinued by the end of the year," with the team's talents now geared toward helping Yahoo transform from a dotcom relic into a mobile company.

For some insight into how celebrity tech investments work, check out The New Yorker's profile of Scooter Braun, who had invested in ten startups, including Uber, Stamped, and Spotify, when the article was published in September.

"Cross-promotion is all part of the interdependent business culture that Braun has created. For instance, he cuts Bieber in on many of his tech investments. Sometimes he has Bieber put money into a start-up company directly; sometimes he offers to have him promote a product in return for equity. “If it makes sense for Justin’s brand, I show it to him,” Braun said. (He has a similar relationship with his other artists, and with Ellen DeGeneres, with whom he has shared tech-investing tips: “She put me onto something, and I put her onto something.”)"

(Photo: Instagram)

Sometimes the hardest question to get a founder to answer is why anyone would regularly use their app. That's particularly true for startups that solve a problem users don't actually have.

But often, the pitch for why X app is better at rating, or recommendations, or social planning relies on the assumption that it will be populated by users just dying to share their personal tastes or make plans  . . . using an app that's on screen four of their smartphone, right next to Draw Something.

That's been the problem with Stamped, a remarkably sleek ratings and recommendations app launched by Xooglers last November that allows users to give their "stamp" of approval to books, songs, restaurant recommendations, you name it.

Back then, we said, "Until we see how many 'friends' opt in, it will be hard to tell if Stamped is a signal, or adding to the noise." And unlike the steady ping of notifications for friends joining Instagram or Pinterest, not many have--and certain few outside the tech world.

That lack of engagement in Stamped, however, didn't stop a stream of celebrity investors including Justin Bieber, Ellen Degeneres, Ryan Seacrest, and Bieber's manager Scooter Braun, from plunking down an unspecified amount in the startup. The New York Times Co. and Columbia Records also went in. As did Eric Schmidt through TomorrowVentures, CrunchFund, and Metamorphic Ventures, bringing the company's total funding to $3 million.

The founders seem to be aware of the problem, which is why they're revamping the entire project, ostensibly moving away from their competition. "We’re a way to share your favorite things," cofounder and CEO Robby Stein told TechCrunch. In version 2.0, social discovery--rather than rating--is paramount. There's a section called The Guide to let you find new things to eat, watch, read, drink, etc. as recommended by the people you follow.

To that end, the company has integrated services like iTunes, Spotify, Amazon, and OpenTable, so you can start acting on the "stamps" that interest you. It's also now available on the web, instead of just mobile. "It should be more like Pinterest and less like Yelp, they determined," Business Insider said of the founders.

TechCrunch noted:

For celebrity watchers, there’s an obvious draw to the new Stamped (what does Bieber like?), and for others, it may be about seeing what books NYT recommends, perhaps. But where Stamped still needs work is helping regular users build up their own collections of things – something that, while easy enough to do, can still feel like a bit of work to do at scale, in order to really create a holistic picture of your interests.

Since the revamp, Mr. Bieber has "stamped" four different things on the app, all of which he mentioned in the charming promotional video below. (Is that Selena Gomez we hear laughing in the background?) For some context, Lance Armstrong seems similarly smitten with his investment, the social networking app Mobli, whereas his fellow investor Leonardo DiCaprio is a little more blazay blah.)

I really like the idea of Stamped, and its design, but stopped checking when it failed to get traction. I hope they can get better engagement in the new framework and convince its celebrity investors to actually use it. Otherwise, why should I?

Correction: An earlier version of this post stated that Mr. Bieber had been a member of Stamped since its launch last November and only used the app sparingly before he came on as an investor. The company informed us, however, that that account was a fake. Betabeat regrets the error. But can you blame us for wanting to beliebe?