Today in Tech: PayPal trumps Square, partners with Discover by JP Mangalindan @FortuneMagazine August 22, 2012, 6:37 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons For AT&T users, FaceTime over cellular Mobile Share plans online; the 10 top startups from YCombinator’s Demo Day. PayPal trumps Square’s deal with Starbucks by partnering with Discover [ALL THINGS D] Under a new partnership being announced with Discover, PayPal is super-sizing the number of U.S. merchant locations it will be accepted at — more than seven million. … Just two weeks ago, Square made a huge splash after announcing that Starbucks would use the start-up to process all of its credit and debit transactions. The new rise of a summer hit: Tweet it maybe [THE NEW YORK TIMES] For “Call Me Maybe,” which was No. 1 for nine weeks, the longest run of the year, the critical piece was YouTube. After Justin Bieber and friends posted a video of themselves lip-syncing to it in February, hundreds of fan tributes followed. Alongside Ms. Jepsen’s own video, which has been watched 212 million times, versions by Katy Perry, the Cookie Monster (“Share It Maybe”) and the United States Olympic swim team turned it into a yearlong audiovisual meme. AT&T only allowing FaceTime over cellular on Mobile Share plans, no extra charge [THE VERGE] AT&T has cleared the air this afternoon on its policies for FaceTime over cellular, saying that a Mobile Share plan will be required to use it — but it won’t incur an extra charge apart from normal data usage. The feature, which is new in iOS 6, had caused controversy several weeks ago when it was revealed that beta builds appeared to block the service on AT&T’s network by default, suggesting that the carrier might be looking to buck the tenets of net neutrality by tacking on an extra charge to enable it. Rumor: T-Mobile to introduce truly unlimited data plan for $30 a month [9 TO 5 GOOGLE] Offering a fix to its $70 not really unlimited data plan that is often capped, TmoNews reported big news this evening that T-Mobile will introduce a truly unlimited data plan for only $30 a month ($20 a month for value customers). That is insanely cheap. I mean seriously. So, what is truly unlimited data mean exactly? The plan will reportedly do away with “speed limits, caps, or overages” for smartphone and tablet owners. Sadly, the plan does not apply to T-Mobile’s hotspots, but rather customers will be forced to choose from the 5GB and 10GB plan offerings TechCrunch’s picks: The 10 best startups from Y Combinator’s S12 Demo Day [TECHCRUNCH] 75 startups pitched their hearts out today at Y Combinator’s 15th Demo Day. We saw surefire small businesses to risky big bets but after collecting opinions from their YCS12 classmates and top VCs, these are TechCrunch’s top 10 picks.