Thanks everybody for your replies and kind words about my photos - frankly, I don't think they are that good (at least, I don't think that most of the time I spend taking them), except for yesterday when I found out that one of my photos was purchased for a magazine, cover and inside + digital use. I was ok to get $30 for this usage, but after having read your explanation I understood that I only get half of that amount! That's disappointing, taking into consideration the usage. Well... Anyway, your replies, guys, are very helpful, thanks again!