Robert Heinlein popularized the now-ubiquitous phrase TANSTAAFL ("there ain't no such thing as a free lunch") in his novel The Moon is a Harsh Mistress. The adage holds today.
Free video services, free email, free social networking tools? No, they're not. Look a little closer.
Alan Patrick nails it:
You're paying for it, one way or another, usually with your privacy.