Looks like iDates.com is being run as a complete scam. Within seconds or registering I was contacted by three women. You have to pay to talk to them so this was all an obvious scam to get you to buy credits ( or coins as they call them). I suspect the recipients are being paid commission on any messages they receive. I’ve seen this scam before elsewhere. The women never take the chat off the site where you could chat for free.
@Simon_Pieman#191126 Welcome 
An update. The site’s Ts&Cs does state in the small print that some of their profiles are fake and messages are sent for “entertainment purposes”. I guess that’s how they’ve lasted so long without being shut down. I’ve found a recruitment advert for people to send these fake messages here:
https://indoleads.com/vi/new-offer-launched-idates-affiliate-program/
It looks as though uksexmeets.com is run under the same scheme as idates.com. I’m guessing the same company? Their Ts&Cs contain this text:
"We aim to entertain and amuse you – and in order to enhance your enjoyment of the time you spend with us, we will employ technical means to engage you in the simulation of flirting with and discovering other attractive people. If we do it well, you may never be able to tell that we are doing it or know when it happens."