This week, Facebook announced that it had made $1.81 billion in revenue in the second quarter, well exceeding the $1.6 billion analysts expected. Even better: 41 percent of that sum came from mobile advertising, once considered Facebook's weak spot.

"Soon we’ll have more revenue on mobile than desktop," Mark Zuckerberg told analysts.

In addition, Facebook said the number of people who signed into the mobile app at least once a month has grown to 819 million, up 9 percent from last quarter.

Wall Street is ecstatic. Since the report dropped, shares have shot up more than 25 percent to touch $33.85 — spitting distance from the $38 IPO price that has eluded Facebook since its disastrous stock market debut, and a vast improvement from its all-time low of $17.58 last September.

"Big picture: Facebook seems to have answered, at least for now, questions about its ability to handle the shift to mobile: Its users are headed there, and it is showing them ads there, and both usage and ad dollars are up," said Peter Kafka at All Things D.

Facebook is selling a lot more ads in general, reaching 1 million advertisers in the quarter. How did Facebook turn around its entire mobile strategy in under a year?

Facebook has become "more successful in attracting small local businesses, aided particularly by a recent simplification of its ad offerings," said Robert Hof at Forbes. He goes on:

Facebook has been particularly successful with so-called app install ads, which make it easy for app developers to promote their apps for quick installation on mobile phones. These ads appear directly in users’ news feeds, making them hard to avoid but potentially more appealing because they’re in the natural flow of what users are doing on Facebook on their phones. [Forbes]

And while Facebook is starting to roll in mobile ads, there's still room for growth. Matt Lynley at Buzzfeed:

Even more promising from an investor perspective is the fact that Facebook still hasn’t hit the gas on a full-blown video advertising business yet — it currently exists in limited form where advertisers can embed videos on Page posts — so it’s very possible that there is further upside in its mobile advertising business. [Buzzfeed]

So after more than a year of giving Facebook dirty looks, it looks like Wall Street is ready to give the social network another chance. "Facebook needed to, and delivered, a blowout quarter," and analyst told The Street. "What is clear from the results is advertisers have validated Facebook as an advertising platform."