Unless you're Google or the government you probably don't have a monopoly in the marketplace. This means you have competitors. In fact, one of the most common mistakes I think people make when they go into business is thinking they have to have a unique idea. If your idea has never been done there's probably a reason. On the other hand if you're running a business with a lot of competitors chances are there's a good demand for your products and services.
To effectively preempt the competition you will have to know something about your competitors. The more you can know about your competitor the easier it will be to find limitations or differences between your business and them. Once you've found these differences it's important you frame them to give your company the advantage. For example_ Some of our competitors offer a similar drag and drop website builder but the websites are produced in Flash. Although Flash allows for some cool animations and effects it's terribly limiting in terms of compatibility and performance. So when talking to our clients we're quick to point out the fact Flash will alienate a huge percentage of the people coming to your website and it won't help you get found on search engines.
If you're unsure about your competitors limitations it's easy to find them. Call them on the phone, buy their product, become their customer. By becoming their customer you'll know exactly what their customers are going through. No doubt all businesses have problems. Point out the problems and challenges your competitors face and then explain how your business solves those same problems.