Watermarks help send all sorts of people to my website. Very small in lower right.
I know that Facebook takes it off when showing the people the center portion of the image (this is done automatically, not by people, by the way), but it shows up in the full image.
All sorts of people find my website, and I let my 720 pixel watermarked images go freely around the internet. It is like water down the river. It goes to the ocean, and then comes back to me again.
In fact, maybe there is a reason why it is called a watermark even though there is no water involved with the digital type of watermark. It's because it truly is like water going to the ocean and then coming back again to me!
5DIII, 5DII, 7D x5, 6D, T2i, T3, 1D X, 10-22mm, 16-35mm II, 18-55mm II, 18-135mm IS x2, 70-200mm f/2.8L II, 24mm f/1.4L II, 50mm f/1.4, 50mm 1/1.8 II x2, 85mm f/1.8 x2, 100mm f/2 x2, 135mm f/2L x2, 200mm f/2.8L II x2, 1.4X III, 2.0X II, 60mm f/2.8 Macro, etc. only had room to list a few Canon items