Unless you're a computer, you are not an SEO expert. Sorry, but it's the truth.
If you're an SEO Company, you merely help businesses rank higher on search engines, but you're not a guru. You're important, but not as important as you think you are, and not in the way you think you are.
The true experts aren't necessarily the ones that KNOW the most information. Rather, they're the ones that understand how to create long-term relationships with others. They're the ones that test strategies endlessly. Most importantly, they're the ones that know how to be honest with their clients when the sticky situations arise.
Are you an expert or do you just think you know a lot?
.... and don't even get me started about email marketing...