Whether you're a small marketing firm, or a fashion magazine, or whatever, your business exists to help people. Trying to be everything to everybody can make this difficult. It can also undermine your authority. Like commandment 5 and commandment 7, this commandment is designed to keep you from wasting time.
Recently I began working with a Seattle company that sells spices, teas, cookbooks, and a few other spice related accessories. The gals I work with on this project don't mind putting my feet to the fire when I screw up, which, full disclosure, I did a lot in the first week. I went to their warehouse to get caught up and smooth out the rough patches. During our meeting we went over the first blog post the team whipped up for them. It was a simple post about different varieties of loose leaf tea, how they taste, how they make you feel, and where to find them.
There were many issues with that post. When I outlined the post in the very beginning, I instructed the writer to include one or two teas not found on their site in addition to the featured teas. She followed my instructions exactly, so when the client brought up this issue with the blog post, I thought I had a well founded defense for that decision. I explained that this was a move to make the post less sales-ey and more authoritative.
The client's response: "Seth, we already are the authority. If we don't carry something, it's because it isn't good enough."
There are many ways to be snooty. The above, I think, is an example of one of the right ways. You can be snooty about your products, you can be snooty about your service. Personally, I chose to be snooty about my clients.
I represent the best, and they expect the best from me. That's just how I like it.