A copyright page serves more than the obvious function. Yes, the most important function is as part of your legal protection against thieft of your intellectual property. But a copyright page can also serve as a clear indication of which steps are required and acceptable for a third party to apply for permission to use content on your website.

It is definitely a benifit to you and to those who use and appreciate your website.

Who knows you could find yourself in the business of providing content to other websites, or perhaps with enough "Used by permission from your domain.com" you will generate a large body of links to your website.