Pros
They train you themselves. Low personal investment. Completely flexible hours - so you can fit this around other jobs. Paid in cash by client, so you get your money the same day. Enjoyable work, social, with regular clients who become friends, and nice companions. Office are friendly, but generally hands-off.
Cons
Very unreliable earnings -from excellent to terrible. Can sometimes earn, £150/a shift or £20. Hard physically, if you do a lot of shifts close together. Girls are competing for shifts and you can't always get the shifts you want. If too many girls are on the same shift - it drives the income down for all. The secret is to work the same shifts each week, gradually you build up a stable of regular clients, who have longer massages and your earnings improve.