My BF used to do these apparantly.
He said like, you'd get one person texting LOADS of different people, acting as WHATEVER...
So the same person could be...
Mary from London who is a 22 year old Blond.
but they could also be acting as
Brian, a 30 year old plumber from York
Btw i have seen those adverts, a lot of them come on channel 5s