Emcee will be a freemium product, but it is currently entirely free.

During the beta period Emcee is entirely free. During this time we will be discussing the actual model, but we feel that the basic service of Emcee should always be free. This means we would charge only for premium additions to the basic service, or requesting payment for high usage. Our roadmap shows some further out plans to develop some premium features into a paid offering, while keeping the basic features (the bulk of what we'd be offering) available to everybody, for free (the freemium model). But this is quite far down the list–quite far down the road.