@Bloombito

Jack Dorsey took the stage with Mayor Bloomberg this morning and officially opened Twitter's first New York office, just in time for Ad Week. "I want to thank the Mayor for his vision on creating 21st century jobs. I know you have an engineering degree, Mr. Mayor, and you may be looking for a new job soon. We're hiring," Mr. Dorsey said.

Mr. Dorsey offered a number of facts related to Twitter and the Big Apple. "New York has the most Twitter users of any city in the world and the biggest community of Twitter developers outside of California," Mr. Dorsey said

Twitter has an upcoming "tea party" scheduled for developers at Betaworks and is eager to tap into the big brand dollars that are based here in New York. "Half a billion dollars have been invested into the Twitter ecosystem in the past year. As big brands look for better tools to harness the power of Twitter, we hope this ecosystem can address this need," Mr. Dorsey said.

Mr. Dorsey name dropped SocialFlow, who is playing host to their tea party; Mark Ghuneim Wiredset, Chartbeat and CrowdTwist.

A daring reporter asked, "What do people in this office do?"

Mr. Dorsey explains that its now mostly sales people with some engineers, but the plan is to build out the engineering staff significantly, a move Twitter accelerated recently with its acquisition of Julpan.

This way to the arcade.

Brush up on your ping-pong skills, advertisers, you're about to get to get the Silicon Valley treatment.

With Advertising Week poised to take New York City, the New York Times reports that the sales and marketing teams of internet behemoths like Yahoo, Google, Apple, and yes Facebook are poised to make good on their Manhattan real estate investments. Although Twitter's new Madison Avenue digs somehow don't warrant a mention.

Rather than flying big brands out to the West Coast, they've set up shop in the Flatiron (Apple's new iAd division), Times Square (Yahoo's new digs), Madison Avenue (Facebook and Twitter are new neighbors), and don't forget the Googleplex East on Eighth.

Those companies will be on display at Advertising Week's 200 events with panels on mobile connectivity, online privacy and social networking, but the real ticket are the baller office parties to entertain clients as the digital world goes searching for their one guaranteed revenue stream: ad dollars. Yahoo has purple conference rooms and door pulls in the shape of exclamation points and Google has a heli pad and, Betabeat's persona favorite, a food truck that sells a mean knockoff of the Momofuku compost cookie.

But Facebook is playing up the startup vibe:

The company’s new office evokes a kind of romanticized view of a Silicon Valley start-up, including an open bar, video games and threadbare couches that reflect the dorm-room sensibilities of the roughly 100 employees who work there.

“When you get to that critical point in terms of the number of employees,” said Carolyn Everson, the vice president for global direct sales, “we like to have a look and feel similar to how Facebook looks and feels in Palo Alto and Singapore and London. And with this market — where we’re all on Madison Avenue and entertaining and meeting with clients every day — we wanted to have a proper presence. And we just weren’t able to do that in the limited space that we had across the street.”

We hope the gift bags include hoodies.

Like its "dream lobbying team" in DC, Facebooks's new PR hires have a strong background in politics. Sarah Feinberg, a former assistant to President Obama, joined its communications team in Palo Alto where her new boss is none other than Clinton-era White House Press Secretary Joe Lockhart. But it looks like Facebook is also looking at the media itself as a potential PR talent pool--Mr. Lockhart worked for NBC in Washington. And Facebook's newest hire is Jennifer Yuille, who will be based in New York--a former producer for MSNBC and CNN. She left her gig as a producer for Katie Couric at the CBS Evening News last year to join Silicon Valley start-up Polyvore.

All Facebook says, "As the company continues to grow and it faces the usual pressures from competitors, regulators, politicians, and the like, Facebook will need professionals schooled in crisis communications and rapid response to react to a 24/7 news cycle." But we think there might be another motivating factor.

When Facebook leased two floors on Madison Avenue back in December, Venturebeat said it signaled a move to cozy up to advertisers--pointing out that the space could house up to 600 employees and that the 15 open Facebook positions for New York were all in sales and operations. Zuck set the tone for Facebook's rocky relationship with ad agencies back in 2007, when he bombed his first big presentation to advertisers by declaring, “Once every hundred years, media changes.” Maybe Ms. Yuille was hired to get Facebook a warmer reception with its new New York neighbors in advertising and media.

Twitter

The little blue bird has been perching in a spartan, open-concept loft in Soho since November, searching for the perfect spot for its first New York City headquarters. Now The Observer has learned that it plans to sublease Facebook's former digs at340 Madison Avenue, according to a source with knowledge of the deal.

Facebook first leased 11,000 square feet on the sixth floor of the glass birthday cake-shaped building, wherein the Office of the Comptroller of the Currency was also housed. It fled recently for some similarly corporate digs just down the street at 335 Madison.

The Grand Central area, a hub of finance wonks and high-end insurance law firms, is far from the lofty spaces and hip organic sandwich joints techies have long preferred. But with the world's two most powerful social media companies just blocks from one another, for better or for worse, it seems only a matter of seconds before the classy office strip is dubbed Silicon Avenue (there, done). The recent deals also place both companies near the once throbbing heart of the advertising industry so lionized by Mad Men and so slowly being supplanted by tweets and friendings.

The deal is said to be a few weeks away. For now, Twitter and its broker, Jones Lang LaSalle, declined to comment. Scott Rechler's Long Island-based RXR Realty, which purchased the building for $570 million in the spring as its first Manhattan investment, also declined to comment.

lkusisto@observer.com