Something be aware of: I used an anonymous email address to sign up with Trip Advisor. I used the same anon. address to create a Facebook profile.

When I submitted a Trip Advisor review recently, they "knew" I had a Facebook profile and a pop-up window offered to link the TA review to my FB profile.

Creepy. Instantly TA was able to access my FB profile, or at least to verify its existence. By the way, I do not have TA's travel tool installed on my FB profile. It seems that FB has sold its email list to TA anyway.

For that reason I will not provide my address to TA for their free cap offer. Presumably it will be sent FB's way.