>It seems to me that memorizing them will make you seem robotic and un-engaging.

It's all in the delivery though, right? You can make a passionate case for your current traction by stating metrics with conviction. You can also recite them in a very rehearsed-sounding way.

I think the point here is to show that you know your stuff. instead of saying "we're growing rapidly" or "approx doubling users every two weeks", have numbers to demonstrate your command of the situation.