Bamboo vs cotton towels

I keep seeing ads in stores (such as Target) or articles in homemaking magazines about the new bamboo towels vs cotton towels. Everyone says bamboo is better because its a renewable resource (as opposed to cotton?), it is more aborbent, and it dries faster. I think the first argument is referring to how quickly bamboo grows, but it's not like cotton grows insanely slowly. And I have a bamboo towel that I got from Target, and I am certain it is not more absorbent than my cotton towel, and it absolutely does not dry faster than my cotton towel. Yet I keep reading these claims. I wonder if my towel is defective.