It is human nature to not value things that we cannot see. So if you think of search engine optimization as
a key component to search engine marketing;
which is a key component to search engine ranking;
which is a key component to generating traffic;
which is a key component to generating sales;
which is a key component to acquiring new customers;
which is a key component to a profitable bottom line;
which is a key component to cash in your pocket!
Then maybe it will be easier to really understand how important it is to have an expert help you with your online marketing plan.
You can always try to do the marketing yourself by writing articles, making your content keyword rich, placing classified ad, etc., but that will leave little time for you to actually run your business. If you are going to try to optimize your site without an expert, you can always opt to get a little help for yourself by buying reports, books or e-books written by experts, and this will save you some time while keeping down search engine optimization costs.
If that is still too time consuming, then you may try hiring a consultant. A consultant can review what you have put in place so far and develop a plan for you to follow. You will still have to do all of the legwork, but at least you will have some assurance that you are running in the right direction.
And finally, if you just do not have the time or the talent to do your own marketing then it would be money well spent to hire an internet marketing expert to manage your online marketing plan. You still can decide how intricate of a plan you require, and you will certainly be able to find a solution that fits your budget.
When you meet with your SEO expert the more clear you are with your expectations and how you will measure them, the better the results you will get from your search engine marketing plan.