If you take nothing else away from this article: think about how your client thinks about your services. Seriously. If I asked you to describe what you do, and then I asked your clients to describe what you do, would they say the same thing?
Most businesses are more focused on what they do than they are on what you do. When they think about your business, they think about it in terms of what you do for them, not what you do.
A good website is focused on everything that the consumer is looking for. If you sell widgets, your website should be about widgets and should help people easily discover what they are looking for about widgets. It should describe widgets how the "widget-seeker" describes them and answer the questions the "widget-seeker" wants to know about widgets.
Good website marketing is using your website to be the solution your customers are looking for. Narcissism is using your website to describe your goods and services, without considering what your consumers are really looking for.