I think this company itself is legit, at least for now, but the risk is that they'll forward this info to 200+ data brokers to "opt-out" - would you really trust them to actually opt you out, as opposed to opt you in (if you weren't already in there) and silently set a flag saying this person is of even more interest? If they can tell that the opt-out request comes from such a service, this increases the value of your profile even more as it's a signal that you might have enough disposable income to pay for such a service.