For social-media investors, it's been an interesting year. The space was once marked by rocketing prices and valuation metrics, but now the trend tends to be a rush to best-of-breed social-media company Facebook (NASDAQ:FB), with both Twitter (NYSE:TWTR) and LinkedIn experiencing losses year to date. Here's some visual context:

FB Chart

FB data by YCharts

So with Facebook experiencing a 44% gain while Twitter has experienced a 19% loss, does this confirm that Facebook is a better social-media play? Or are investors overlooking Twitter's potential going forward? Here's what investors should look for to in the years ahead for both companies.

Facebook's revenue growth is amazing and should continue
Facebook provided amazing revenue growth from 2011 to its last annual report by growing from nearly $3.7 billion to $7.9 billion, a gain of nearly 46% per year. For perspective, last quarter Facebook made more than it did during its 2010 fiscal year. Facebook's been able to do that through aggressive ad-based revenue growth during that period.

In addition, Facebook has a couple of revenue growth drivers that haven't fully contributed to its bottom line in a meaningful way. The company's $1 billion Instagram acquisition is still far from full monetization. Facebook appears to be more focused on growing users before rolling out ads in a substantive manner. The company is working on targeted ad campaigns to monetize users, and CEO Mark Zuckerberg says that "Instagram is a few years from being an important business for us."

The company's WhatsApp acquisition hasn't appeared on the income statement, either. After Facebook paid $22 billion for the text messaging service that charges $0.99 per user per year, making the Instagram purchase seem outright cheap, the acquisition closed earlier this month and should appear in upcoming reports. The $2 billion purchase of Oculus should also contribute to revenue in the years ahead.

However, with these purchases Facebook is taking a long-term focus. While the company will continue to derive the majority of its revenue from its namesake website and app, the company is looking to broaden its revenue sources in the years and decades to come.

Twitter's revenue growth continues
Twitter appears to be focusing on two main methods of monetization: ad-based revenue and data licensing. And although it's less diversified as far as monetization drivers go, Twitter isn't as far along on the maturity scale and thus has higher revenue growth rates. The company has grown revenue from $106 million in 2011 to $665 million in 2013, for an outstanding 150% growth per year.

Top-line growth has continued throughout 2014, with a 127% increase over the year prior. And while the its monthly active user growth has slowed, the company has continued to grow ad revenue per 1,000 timeline views to the tune of $1.60 last quarter, exactly 100% more than last year's comparable quarter's figure of $0.80. So although the market has cooled off on Twitter's future this year, mostly as an overreaction to the extreme bullishness that gripped the company post-IPO, the company has improved operationally by better monetizing each user.

Final thoughts
Facebook continues to grow its ad-based revenue and has acquired multiple revenue drivers that haven't shown up on its income statement in a meaningful way so far. Twitter will have a bumpier ride as it continues to focus on both growing and monetizing its timeline views. And for that reason, I think Facebook is a stronger social-media investment at this time.