Zynga Continues to Cut Ties With FacebookZynga and Facebook pull away from each other, Pinterest beefs up its engineering team, YouTube hits one billion monthly users and more social-media news.

This week's need-to-knowsocial-medianews.

Zynga, the social gaming company whose runaway hit FarmVille made it synonymous with Facebook games, is now pulling away from the social network that nurtured it. Starting next week, players will no longer be required to sign up for a Facebook account in order to register on Zynga.com. And Zynga games -- many of which encourage in-game purchases -- will use the gaming company's own currency instead of using Facebook as a payment processor. Facebook takes a 30 percent fee on those transactions. In 2011, Zynga accounted for about 12 percent of Facebook's revenue.

The disengagement is mutual. Facebook plans to withhold certain information about its users' social graphs. For instance, Zynga users will no longer be able to see their Facebook friends who are playing Zynga games but with whom they haven't previously interacted. Although Zynga would prefer to have full access to Facebook user data, moving away from the company's former dependence on a single platform seems the right choice.--Wall Street Journal

YouTube reaches a billion monthly users.
YouTube says it now has 1 billion monthly users. If YouTube were a country, it would be the third-largest in the world, after China and India. The video service is so powerful and well-known around the world that it's an advertiser's dream: Every one of Advertising Age's top 100 brands has run a campaign on YouTube.--CNET

Pinterest acquires a recommendation app.
Less than a year after local recommendation app Livestar launched, it has been purchased by Pinterest. Livestar will be shutting down and its engineering team will be joining Pinterest. "We think the Livestar team is a natural fit for Pinterest because of their commitment to inspiring people to do things in their everyday lives through social and expert recommendations," Pinterest said in a statement.--GigaOm

Happy birthday: Twitter turns seven.
推特turned seven years old this week -- a benchmark for taking stock of the company's explosive growth. "As we've grown, Twitter has become a true global town square -- a public place to hear the latest news, exchange ideas and connect with people all in real time," editorial director Karen Wickre wrote in a blog post. The social network now has more than 200 million users creating more than 400 million tweets every day.--推特Blog

From Facebook to face time: one man's attempt to reconnect with friends.
When was the last time you saw each and every one of your friends on Facebook? A Connecticut-based photographer is determined to meet all 788 of his Facebook friends in real life. What's more, he plans to take their photos and to make a documentary about his journey. He has raised more than $13,000 on his project'sKickstarter page, with four days of funding left to go. "The goal of this project is to reconnect with people. No more hiding behind the screen of social media," Morin writes. Ambitious of him, isn't it?--ABC News