I must have been really sleepy when I wrote that message.
Coffee grounds do make a great fertilizer. What I meant to say was that the mechanism by which it work is indirect. The coffee is not taken up by the plants directly. What happens is the coffee grounds get eaten by soil microbes which produce plant foods. The process takes about 3 weeks to work so if you get on a regular program of fertilizing with coffee grounds, your soil and plants will love you!
You can usually get lots of free coffee grounds from all your local coffee shops simply by asking.