Depending on what country you live in, review websites are not a problem(unless you live in China or Cuba). The biggest complications you will encounter legally will relate to your TOS and Privacy Policy. Your privacy policy goals(outside of the standard TOS terms) should reflect:
1.) Demographics information collection for user signups via Facebook/Google/Twitter and your google analytics demographics information.
2.) ****** Aligning your TOS with collecting SRED and Media Tax Credits for the development of the website and marketing. If you do this correctly, you should receive 30-40% back from your original investment.