I did not register a copyright on a literary work, and it was stolen/infringed. What are my rights?

I had a written "sales pitch" on my home page, and a paragraph of it was copied and pasted on a competitors website. I did not have this work copyrighted, but I heard that some works are copyrighted at creation. I've also read that before an infringement suit may be filed in court, registration is necessary for works of U.S. origin. So then the magic question is, what forms of relief could I be able to get? sue for injunction? or would that not be cost-effective I am uming.