The Latest Must-Stop for Celebs on a Promo Tour: Silicon Valley With television audiences diminishing as a result of newer digital mediums, celebrities are increasingly courting the tech giants of Silicon Valley on their recent promo tours.

The late night landscape forever changed when Jay Leno passed The Tonight Show torch to Jimmy Fallon earlier this week. But lately, as television has given way to competing digital mediums, celebrities in promotion mode have been making the rounds on a totally different circuit -- within the hallowed halls of Silicon Valley.

On a promo outing last week for her new book -- whose cover she debuted on Instagram -- Lena Dunham stopped by the offices of both Twitter and Facebook to meet with staffers and host an in-office Q&A.

During her Twitter visit, which coincided with Valentine's Day, Dunham was interviewed by the company's consumer communications manager, Elaine Filadelfo -- a conversation that was unsurprisingly live-tweeted by a several Twitter employees. One even gave her a long-stem red rose:

@lenadunham here's you at Twitter HQ: pic.twitter.com/RUUstVXcJD

— Tim Trueman (@timtrueman) February 16, 2014

At Facebook, Dunham hung out with famed COO -- and fellow author -- Sheryl Sandberg, as well as Instagram founder Mike Krieger.

The Girls creator -- who boasts over 1.4 million Twitter followers herself, and roughly half as many as that on Instagram -- is only the latest in a long line of celebrities courting the vastly influential titans of Silicon Valley to tout their latest projects.

As far back as 2010, Kanye West astonished Facebook employees when he debuted previously-unheard tracks from his My Beautiful Dark Twisted Fantasy album -- at the company's headquarters while rapping a cappella atop a conference room table.

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Days later, West graced the Twitter offices with a similar performance -- on the very day that he first joined the site.

Ahead of the release of her sophomore album Born This Way in 2011, Lady Gaga dropped by Google's California campus for a tête-à-tête with Marissa Mayer -- then-vice president of user experience. Many Google employees dressed in their best Gaga getups, while the singer discussed her intense love for social media.

Most recently, Miley Cyrus jetted off to Silicon Valley promptly after premiering her new single We Can't Stop -- foregoing day or nighttime talk shows in order to schmooze with staffers at Instagram, Facebook, Twitter and Vine.

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