What am i doing wrong?

I'm registered on one of those dating sites to meet women. I know this specific site works because i've had friends who have met other women from it. One of them is still with this girl he has met over 2 years ago. I haven't met any women and very few have ever responded back( about 2 or 3 out of about 40-50 women). I can't show the profile because a) not in English and b) need an account to access it. Anyway, what are some ways to gauge a girls attention on the site(my profile) and what can i write in an email so they actually respond back. Please, girls only answer unless there are any guys who have had any success.