It's an interesting concept, though I don't know if I understand how this will help people improve their sex life. It's just about sharing secrets anonymously, right?
I can't see it improving anyone's sex life. Even with 24/7 moderation to weed out the joke/troll posts (which I can envisage a site like this being a real honey-pot for), everyone's tastes and desires are different. So the best way to improve your sex life will still be the old fashioned methods; to read their body signals (it shouldn't take a genius to tell if you're turning on your partner) and even just to talk to them (assuming you're in a relationship).
See you are totally right what you say it is about communicating (listening, understanding and talking). Unfortunately this does not come so natural to everyone and talking with sexologist they tell me that the (lack of) good communication is what brings their patients to see them. Sexycrets wanted to give some better tool to improve this communication.
Well, at first one of my ideas was to allow users to vote the tips they liked most and having them matched with other users (of the sex they were interested into) interested in doing the same things.
Also for already established sex relationships I thought this could have been a tool where both can select what they like and we show them just what they both like. In this way we take away the negative embarrassment of getting your ideas refused. What about it?
Best of luck to the OP though.