Water marks with company’s name or URL is a good alternative to protect your images from getting stolen, however this makes the image a little untidy. Is there any other way to protect images against image theft?
A copyright watermark can still be added to make it obvious you don't want to share, and the watermark can be unobtrusive. However, an unobtrusive watermark tends to be easier to remove unless you go out of your way to work it into each image naturally. Steganography is another option for watermarking in an invisible way, if you're just looking for ways to prove that the image is yours, but it's more complicated.