If you show any interest in a profile, they'll contact you and engage in conversation. They won't speak to you outside the site, using security etc. as an excuse. At around a £1 per message, it adds up very quickly. The profiles are fake, if you report a fake profile, they retire that profile and use another.
The profile that contacted me made me suspicious because a) when asked where they were from, they said Leeds, born and bred. However it was obvious English wasn't their first language. They also wouldn't talk outside the site, despite being given both my FB account and phone number.
Last but not least, their profile pic had a website logo on it, they couldn't tell me why.