I think I have slightly differing views on some of this subject to a lot of you due to how I started out and the different accepted norm in the face painting industry to the balloon industry.
In face painting no one expects credit if you copy their design and it is the same if you follow a step by step or DVD. However, if you "borrow" a face painters photo from their site or elsewhere then expect to be hunted down like a dog and made to remove them.
If posting on here I usually try to credit whoever I saw the design from first but I am sure they either saw the design before themselves or at least saw elements of those designs somewhere else and put them together so it can be a little tricky.
As I said before though if I have made the model (whether it be from a dvd or a picture I have seen) then on here I am happy to credit (if I can remember) but on my website I prefer not to. Firstly, because I don't think the general public care who came up with the design and secondly my website is my marketing tool and in the nicest possible way I do not wish to promote my competition especially since a few of you will cover my area

. It is my belief that parents simply care whether you live up to the same standard as your photos as that is what they based their decision to hire you on.
When I have been on jobs I will never claim credit for someone else's designs if I am asked if I "made it up" myself but I rarely tell them the name of who did - mainly cos I can't remember my own name sometimes.
Graeme re your photo being used by the company to advertise a different artist, whilst this is not legally wrong it certainly is morally wrong. Unfortunately, when working in public if someone takes a photo of you they own the copyright and can use it for any purpose they see fit.
I do, however, believe things like your photo being used for an inferior acts show will do nothing but harm to our industry. I presume that the people attending the show would have been seeing it as part of their holiday package and not paying extra but in any event may have based their decision on whether to see the show on the advertising. They will then get the impression that a lot of twisters / magicians etc use others photos because they are really rubbish and they will be put off hiring someone because they cannot be sure that they will get the standard they see on a website or flyer.
As for people staling your act Graeme that is terrible and then to deliberately undercut you too is even worse. That is another reason why I now concentrate more on the balloon side of my business than the face painting as there are too many cheap and cheerful painters round here charging around half the price I do and I just cannot compete in a not very affluent area and in a recession.