I feel sorry for anybody with no real aptitude who goes this route. Basically all he/she/it is learning is interview technique. Most of the info is here on-line for free; if you have no aptitude you will - hopefully - be caught out further up the line. However by that time you have wasted a lot of people's time and money.
BTW If the person operating this service is employed by NATS would he/she be required to declare his/her involvement?