This link takes you to a site that advertises "FREE" cell phone look-up searches. The "SEARCHES" are "FREE"--the information they retrieve is NOT FREE!
Essentially, the "FREE" part is to find out if you can PAY them for as-yet undisclosed information.
It's kind of like Best Buy putting up a banner on their stores saying "FREE BLUE-RAY PLAYERS!," meaning you are freely allowed to come in and look at the merchandise for free. The only difference is that at Best Buy, you actually get the chance to inspect the product first!