Despite all of your best efforts, factors can combine to make a relationship between your organization and an SEO firm not work. The problem can be in the relationship, in the SEO strategies, or even in some other aspect of the situation.
The question is, what do you do if you find that your SEO firm (or an individual SEO professional) is just not what you expected?
There’s no easy answer to that question, unless you address it at the very beginning of the relationship. If you address it early, you can include a clause in your contract that outlines the situations under which either side can terminate the relationship.
If you don’t address the possibility early, however, you may find yourself stuck with an SEO firm or professional that’s doing nothing for you except running up a big bill.
Do whatever you can to protect yourself. Know your contact at the SEO firm, and how to reach that contact when you need to ask questions or find out why something is (or isn’t) happening.
Your relationship with your SEO firm should take the same structure that a relationship with any other provider takes. Don’t think that, because SEO is different from using a hosted technology or dealing with a service vendor, it should be governed by less stringent requirements.
SEO is a service for you, and the relationship is like that with any other vendor. Just as much attention should be given to it.