Cashcrate pays you for signing up with *other* sites. These other sites, which are not controlled by Cashcrate, will spam, call, and mail you. You should therefore not give them your real phone number and address unless you want to follow through with the offer. I recommend you use a spamgourmet email: [Link](Mouse over link to see full location)
You do need to give Cashcrate itself accurate information. They will not spam you, and they'll only call once to confirm your phone number.
I don't see why your parents would have a problem with the site. It's entirely safe if you don't give accurate information on the offers. A credit card is not required for most of them, and Cashcrate tells you when one is.
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