I signed up on those Cupid plc websites in the past. It's a scam and let me explain their modus operandi. Most of the decent profiles are fake. They have profile images picked up from the Internet (and you can confirm this by reverse looking up the image on Google). It is definitely a fraud scheme. You will receive a lot of emails from many genuine-looking people till you sign up (all the content in the email will be hidden, the profile image of that person will be so tiny that you wont discern anything). Every day you will get an email you are popular and you should pay them money to contact people, all fake and obviously bots!
Once you sign up, these emails from seemingly real people stop coming. You can also notice that the profile images are photoshopped or fake (because they now let you see the bigger image). Most of the traffic that lands up in your inbox now is spam, sent by the website itself. They also automatically sign you up on their many sister websites (cupid.com, girlsdateforfree.com, datingforparents.com, speeddater.co.uk, uniformdating.com, loveagain.com, maturedatinguk.com etc…) and you start getting the same type of spam from them, all begging for you to sign up. Horrible extortion scheme. I am sure there are better ways of making money than playing with people's emotions. The profiles of the people are not genuine at all; they are all fake people who have posted their profiles. Messages before you sign up are definitely fake and bot generated.