Well my answer is yes watermark all you work. If  in fact I think almost everyone  should watermark all their art work…. Maybe then we will get a little respect…recently I was chastised by a band for putting watermarks on my work…this person went off on a rant because I watermark a musician he liked… I might add that this person is from a semi famous band …I have had my work stolen by bands that say they will at least tag me but have not…I have had people take my images and the lab that blew up the picture got paid more money then I did. When I go to a show I carry about $20,000 dollars on my back… I want to show my work in the best possible way but when I do people  want the work for free..I went to school , I paid for my equipment by working other jobs…everything I make goes back into equipment…stop giving your work away for free…I have heard every excuse in the book… “I am saving for my video” “I don’t get paid” “my (brother , mother , sister , girlfriend , friend will do it cheaper” I am good at what I do…but I am tired of everyone else getting paid but me… the music store does not give you a guitar  or amp  for free .. the gas u need to get to your gig is not free .. why do I have to be…so watermark all your work… let people know who you are