What's that? Everyone's falling in love with Facebook (META 3.08%) again?

Shares of the world's leading social networking website operator soared today after posting encouraging quarterly results last night.

I got brazen over the weekend, offering up four reasons why the stock was likely to head higher this week. I blow many calls like that, but since it appears as if I got this one right, I figured I would take a closer look at the four reasons in light of the report.

1. Earnings should soothe the bulls
Facebook merely met Wall Street's profit target of $0.12 a share in its first quarter as a public company three months ago. It held up slightly better this time around, surpassing the $0.11 a share that Wall Street was targeting.

Sure, Facebook's adjusted profit of $0.12 a share simply matched both its year-over-year and quarter-over-quarter mark of $0.12 a share, but resilient profitability and a 32% spike in revenue suggest that Facebook is just getting started.

"Until Facebook gives investors a reason to panic about its financial fortitude, don't panic," I argued over the weekend. I was right.

2. The upside to Google's downside
Google's (GOOGL 1.23%) disappointing report last week weighed on shares of Facebook and Baidu (BIDU 1.24%).

The connection didn't make any sense, especially since Google was hitting new highs earlier this month as Facebook and Baidu were struggling.

Google is being marginalized out of China, and the world's most populous nation has proven in the past that it's working on a different growth trajectory than the rest of the world. There's a big difference between where a mature Google is in its growth cycle and where Facebook is as it's just starting to monetize it gargantuan traffic.

The market was shocked to see that there was a 15% drop in the average cost-per-click at Google, but that metric has been stubborn for several quarters now. Facebook has actually been getting advertisers to pay more to generate leads on its website, so it wasn't a surprise to see Facebook come through with a 38% surge in ad revenue. This is huge, because advertising now makes up 86% of Facebook's revenue.

The dip last Thursday afternoon in Facebook shares after Big G's disappointing report was a buying opportunity for Facebook investors.

3. Facebook is cheaper than you think
I think even bulls agree that Facebook had no business hitting the market as a $104 billion company when it went public at $38 five months ago.

However, isn't a more proven and growing Facebook worth more than half that price? This is where Facebook was over the weekend, with its $19 close pointing to the mother of all "half off" sales.

Facebook wasn't cheap at 30 times forward earnings then. It's not any cheaper, obviously, after Wednesday's pop. However, investors shouldn't be dismissing Facebook just because it was mispriced out of the gate or because it performed badly as a result of that miscalculation.

This is a company that just cranked out an adjusted profit of $311 million on nearly $1.3 billion in revenue over the last three months. This is a nearly 25% net profit margin, and Facebook is just getting started on the monetization front.

Think about that.

4. Don't fear the mobile future
One of the biggest reasons for Facebook's pop is its encouraging outlook for mobile monetization.

It's not happening now. Just 14% of its ad revenue was generated from mobile devices, even though 60% of its billion monthly active users are now engaging with Facebook in one way or another through mobile apps.

That will change.

"I think our opportunity on mobile is the most misunderstood aspect of Facebook today," CEO Mark Zuckerberg said during the call. "I believe that over the long run we're going to see more monetization per time spent on mobile than on desktop."

It's a lofty goal, but keep in mind that Facebook didn't even start trying to make money off of its mobile app through advertising until earlier this year, yet it's already drumming up $50 million in monthly revenue that way.

If today's pop isn't commanding your interest in -- or at the very least respect for -- Facebook, you're just not paying attention.

A world of opportunity
There's a new premium report on Facebook detailing the opportunities and challenges in store for its shareholders. The report includes a full year of updates, so time's ticking. Check it out now.