Now, in my humble opinion, marketing is also about communication- on a person to person level, and if you work in SEO this should be manifest in your client relationships. That doesn't mean that your SEO consultant should be a super-communicator, but they should at the very least understand that you have the capacity to comprehend what it is that they do for you.

If you're currently working with an SEO consultant, or are looking for one, there are some questions that will help you sort the good from the bad- they're not about rankings, or visits, or the long-tail, they are to assess whether that SEO is fundamentally any good at their job.

Do they:
1) ...encourage you to ask questions?
2) ...give you satisfactory answers- if you're not sure if an answer is satisfactory, it's not
3) ...endow you with the sense that you are key to the optimisation process/cycle?
4) ...openly acknowledge that certain things are out of their control- and tell you what they are, without any flannel?
5) ...appear genuinely enthused about SEO?

If the answer to any of these is "no" then think about what that "no" really means to you.

Asking questions is a good way to learn, and a great way to show interest- more importantly though your spending needs to be justified. People who don't like being asked questions are trouble, and people who give unsatisfactory answers more so.

Bearing in mind that you are the client, you know your own business and industry better than any SEO consultant can. Being made to feel that you are a key part of the SEO process/cycle is not about ego-massaging, its about the SEO getting useful info out of you- to put to good use on the work that you are paying them for.

No-one likes it when something is out of their control. It can sometimes take a steady nerve to share facts that may appear, in some small way, to undermine your own credibility. We SEO's don't know the intricate workings of the search engines and their algorithms- we can see trends, identify better ways of doing things etc. but we can't guarantee that your #1 position will still be there tomorrow- we will work to keep it once it's there though.

...as for the one about them appearing genuinely enthused about SEO, that's a no-brainer.

Overall, when an SEO shares knowledge and is happy to teach you something it shows confidence and respect, confidence in their own ability, and respect for you, and their relationship with you.

So, if your SEO consultant is afraid of teaching you, or sharing knowledge then perhaps they don't have too much to offer in the first place?