there have been a dozen threads on this subject. there are many people that think its now a part of the image including artists. many are confused. i don't mark them. and i wanted them marked i would have to ask to have them put on and put off. and who needs that? plus i can't add up in a week, because i don't get constant sales. and you'll never know the sales you lost due to the mark. why take the chance? the mark can be removed very easily, it doesn't show up on white at all, doesn't say who the image belongs to, they can't trace it back to you.
and mostly - it does not encourage sales.
---Mike Savad
MikeSavad.com