I often read about watermarks and how many people think that they are automatically a good thing. After all, they do make it a little bit more difficult to steal the photo (not much, but a bit) and they do often show people who took the photo. All good, you might think. But - there is a downside.
The biggest problem with watermarks is that they put off reputable publishers, like thisiscolossal or boredpanda. You will notice that no photos with watermarks appear on those sites and if it were not for those sites, particularly thisiscolossal, I would sell very few fungi images. So, the choice is - put on a watermark and get some recognition from the small, unimportant sites, or - skip the watermark and get publicity from sites that customers really take notice off. To make that even more specific, since thisiscolossal first published my photos, I have had almost 10 million photo views on my websites and I have had a steady stream of paying customers. I know a professional photographer who has been trying to get his photos shown for years on this site and no luck, because he knows that they are give great exposure. I suppose it is possible that thisiscolossal would have asked me for non-watermarked versions of my photos, but that is a lot of extra work for them, and me, and I doubt that they would have bothered. As it was, all they needed to do was send me an email asking for permission, I replied with a yes and they made the article. Done, and things have taken off from that point. They have even done another article a year on from the first one. The people who steal the photos are irritating, but am I going to shoot myself in the foot to try to stop them? After all, a facebook site that gets almost 100 shares of my uncredited photos is unlikely to be significant compared to 86,000 shares from thisiscolossal which gives credits. And then you need to consider the people who subscribe to thisiscolossal.
My view is that I would only make a fraction of what I do if it hadn't been for thisiscolossal and that I wouldn't have been on thisiscolossal if I had used watermarks.