Efforts by Zynga (NASDAQ:ZNGA) to reduce its dependence on Facebook (NASDAQ:FB) are taking hold, but not at the rate some investors might hope, Fool contributor Tim Beyers explains in the following video.

According to its latest 10-K filing, Zynga derived 69% of bookings and 75% of revenue from Facebook in 2013. Huge numbers, to be sure, but also down from 2012, when Zynga counted on the social network for 81% of bookings and 86% of revenue.

Impressed? Don't be, Tim says. The ratio is far higher than others who hope to take Zynga's place as a go-to for mobile gaming. Take Kabam, which recently acquired peer Phoenix Age and is aiming for as much as $650 million in 2014 revenue -- an 80% increase, according to TechCrunch.

Games hosted at Facebook and Kabam.com accounted for just 30% of revenue as of this writing. Candy Crush Saga maker King isn't as specific in its disclosures. Instead, the company identifies Facebook and app stores from Apple, Google, and Amazon.com as the source of the majority of its revenue.

Therein lies the problem for Zynga investors. Kabam, King, and others have already figured out how to distance themselves from Facebook while enjoying huge growth. Investors need Zynga to achieve the same soon, or risk watching the company get permanently left behind.