Viralheat is probably best-known for its social media analytics and publishing tools, but it also offers some free APIs. And at least one of those APIs, the one that analyzes sentiment , is taking off, according to CEO Raj Kadam. He tells me that Viralheat originally intended to use another company’s sentiment API, except he wasn’t satisfied with what he found — everything focused on keywords, rather than using natural language processing to glean the true meaning of a tweet or comment

A number of third-party ad providers are reporting early success with Facebook’s new mobile-only Sponsored Story advertisements .

Recruiting startup Interview Street is making a move onto college campuses (virtually speaking). The company helps employers recruit programmers by holding online coding contests to test their skills .

“I don’t want to talk about whether ads are good or bad. I just want to make good ads. Good for apps, good for users.” That’s from Kiran Belubbi, founder and CEO of 955 Dreams which today added the most gorgeous mobile ads I’ve ever seen to its app Band Of The Day

Every once in a while, I’ll stumble on the Twitter account of a celebrity I admire. Once I get past my moment of “OMG, it’s Neil Gaiman !” (or whoever), I try to browse their tweets. Sometimes, the browsing ends with, “Awesome! Follow!” Other times, I’m left thinking, “God, I have no idea what’s going,” because their tweet stream is dominated by incomprehensible conversations with people I don’t know or care about.

PayPal , the eBay-owned online payments service that is making significant inroads into mobile, is giving its website an overhaul to make it easier for its 100 million+ users to pay and get paid, find help, and potentially start using some of the newer services that PayPal is pushing hard to grow. The redesign also happens to look a lot more touch-friendly, perhaps a sign of how much tablets, smartphones and the mobile web figure today in the company’s strategy.

The Oatmeal’s Matthew Inman wrote an open letter to the lawyer who has been harassing him for most of two weeks , Charles Carreon. Carreon just sued Inman as well as the World Wildlife Foundation and the American Cancer Society. You can see some background here but this is all as crazy as it sounds

Q&A site Formspring  is today announcing what the company says is its biggest news since its original launch back in 2009. Yes, Formspring has been overhauled. The company is shifting its focus from social Q&A, to a site that’s more focused on conversations built around interests. To complement this change, Formspring is also rolling out a completely redesigned website to highlight the company’s new direction.

After a late start we arrived in Philly and talked to a number of cool folks at Office Hours. Now it’s time to party. Josh Zelman, Jordan Crook, Chris Velazco, and myself will be at the Field House at 6pm and we’re ready to talk startups, tech, and all things in between.

Next week, Google is holding its annual I/O developers conference in San Francisco, but that’s apparently not stopping the company from making some developer-focused announcements now. With Google Developers Live , which is launching today , the company plans to “bring you the excitement of Google I/O year-round.” As Louis Gray, a program manager on Google’s developer relations team notes (and here we thought he was working on Google+), Google plans to use this new site to “feature live, interactive broadcasts ranging from developer-focused game shows to Office Hours where you can connect with the engineers who created and work on your favorite Google product.” Most of these programs, it seems, will also feature interactive Q&A sessions. The service, Google says, will use streaming video and Google+ hangouts to connect Google’s engineers with the developers that use their products.