I honestly don't think they knew it was wrong (seriously, because if I thought they did I'd be all over them about it) but now I'm faced with figuring out what to charge for something like that. Not for this one (a slap on the hand will do) but for all future images that a client would want to use for print advertising after the session took place.
So here are my questions:
1) What is the going rate to use 1 image for print advertising?
2) Do you price per image or is there a package deal?
3) Would you offer the image for commercial use for photography credit only instead of payment (seems like a fair trade since they're paying for the advertising)?
4) I should've had them sign a contract that explains the copyright, huh?