The success of the promotion was revealed by Chair publicist Laura Mustard in an interview with AllThingsD. She revealed that 1.7 million downloads occurred on the first day of the promotion, totaling 5.7 million by the end of the week.
Those downloads came in three times faster than usual for Infinity Blade II, one of the premier gaming titles available for iOS. The game usually costs users $6.99 to download.
The game was one of a number of titles that Apple made free last week to celebrate five years since the iOS App Store opened. Others included Superbrothers: Sword and Sworcery EP, Traktor DJ for iPad, and Barefoot World Atlas.
Though the 5.7 million downloads of Infinity Blade II were given away, Chair and publisher Epic Games may still come out on top, as the title also includes in-app purchases that allow players to obtain in-game currency for upgrades more quickly.
The sale also had a ripple effect, boosting downloads of the first "Infinity Blade," available for $5.99, by 2.5, as well as the $2.99 e-book title "Infinity Blade: Awakening" by 70 percent.
The success of Infinity Blade II came as another title, "Infinity Blade: Dungeons," was canceled by Chair and Epic. That game was shown off last year alongside the third-generation iPad with Retina display.
However, Chair Entertainment has confirmed that the Infinity Blade franchise will live on, with more games, books and other products said to be in the pipeline. Publisher Epic has also said that the "Infinity Blade" series on iOS is its most profitable series ever, even eclipsing the blockbuster "Gears of War" title for Microsoft's Xbox 360 console.