Apple says 15 billion apps have been downloaded from the App Store, a rate of growth nine times faster than that of McDonald's hamburgers.

Apple announced earlier this month that after three years of operation, the App Store had thanks to more than 200 million iOS users. By comparison, Google's Android Market hit 4.5 billion downloads in June.

ZDNet's Eric Lai published an infographic to show how the growth of Google's Android Market and Apple's App Store compare to what he called the "Gold Standard for Incredible Growth, McDonald's hamburgers." To compare the growth of these app stores to McDonald's burgers, check out this infographic, created by Andrea Love from Sybase.

The iconic golden arches come stamped with the phrase "billions and billions served." The signs used to include a number, which Lai says McDonalds stopped updated in 1994 when it reached 100 billion burgers. It took McDonald's 26 years to serve the same number of burgers as the number of apps that have been downloaded from the App Store, and it took the fast food restaurant an additional 20 years to hit 100 billion burgers.

"That means Apple hit the 15 billion mark about nine times faster than McDonald's," Lai said. "And based on projections, Apple could hit 100 billion within five and a half years, or about nine times faster than McDonald's."

Lai also noted that "based on projections of its accelerating growth, Google could hit 100 billion downloads even sooner than Apple."

In 2010, the mobile app space became a billion-dollar industry and this year revenues will continue to grow, soaring from $2.1 billion to $3.8 billion in 2011 according to . As far as iOS is concerned, Piper Jaffray analyst Gene Munster that purchases from the App Store will grow 61 percent this year.

But the Android Market is growing aggressively too. It debuted in October 2008, just a few months after Apple launched the App Store. There are an estimated 250,000 apps in the Android Market, and Google's Andy Rubin that wireless providers are activating 500,000 Android devices each day.