The conciliatory tone toward Apple that sources close to Facebook’s Project Spartan expressed earlier this week may be the best way to proceed, since it will be difficult for anyone to approach the numbers Apple announced Thursday.

The Cupertino giant said more than 15 billion applications have been downloaded from its App Store, by more than 200 million users of the iPhone, iPad, and iPod Touch.

Even with Facebook Chief Executive Officer Mark Zuckerberg confirming that the social network has reached 750 million active monthly users, catching up to Apple’s total would require each of those Facebookers to download 20 apps from the platform eventually generated by Project Spartan — not likely, considering that most will probably not even download a single one. At least not right away.

Apple Senior Vice president of worldwide product marketing Philip Schiller boasted:

In just three years, the revolutionary App Store has grown to become the most exciting and successful software marketplace the world has ever seen. Thank you to all of our amazing developers who have filled it with over 425,000 of the coolest apps and to our over 200 million iOS users for surpassing 15 billion downloads.

Readers: Once the platform resulting from Project Spartan is up and running, would you be interested in downloading apps through it?