I often get asked, "Do you watermark your images before you put them online?" The answer is Yes AND No.
I capture Individual portraits and allow clients to choose their favorite 3-5 images themselves out of the majority of photos captured. I then create digital "proofs" of the entire collection and add my watermark at this stage of the editing process in order to deter copying.
However, once the images have been edited, the final copies do not contain my watermark. It is not a part of my business practice to charge the client an additional fee for a "logo-free" version of the image. It's really a matter of personal preference depending on the subject matter... Now, if you sell your images as stock photography or as fine art, I'm a huge advocate of watermarking. Good luck!