If I order a package from a company selling a good, am I inviting all that company's competitors to show up at my doorstep to try and outbid the delivery person from the original company when they arrive, and maybe they all show up at the same time and cause my porch to collapse? No, because my front porch is a limited resource for which I paid for an intended purpose. Is it illegal for those other people to show up? Maybe not by the letter of the law.