Looks like a scam, given that you have to register to see anyone. 

It's a SCAM !!
This agency wasn't even started until 17th April 2009, ( check Whois) how can they have a huge database of clients already? A genuine agency will allow you to view their escorts for free. Like many others, this site is based purely on getting people to register as escorts. There is no way of viewing potential escorts without becoming a member.
The reality is that most "gentlemen" book an escort on the spur of the moment. They will not pay to see who is available, plus pay for their services....it doesn't work that way.