There's no doubt that Chair's Infinity Blade has become a significant hit, and Epic's Mark Rein has cemented the fact with a little bit of perspective -- proclaiming the title to have eclipsed Chair's other critically acclaimed title, Shadow Complex.
Rein didn't specify in what way Infinity Blade's success had outpaced the XBLA's title's, but one can reasonable assume that it's been downloaded more times, and quite possibly made a lot more cash despite the lower price of $5.99 (now $2.99) as compared to $15.
Best of luck to 'em, though. I'm still playing Infinity Blade, and it's easily one of my favorite games ever. Chair deserves all the success it's gotten, and then some.