Often clients want to have their website optimized for the search engines.  I agree it is an important piece of developing a website.  But it can’t stop there. Optimizing your site does not mean you will suddenly appear on the first page of Google, Bing and Yahoo – just means when your site is submitted to the search engines they can recognize what your website is about, but unless you have a lot of content already on your site about your subject area, then you are going to need a lot more work.
I recently discovered a previous client’s website that we had optimized and was being found on the front page in most searches related to his field, that he has recreated without the optimization and now he is on page 3 or 4.  Not only does he not have his pages optimized but none of his blog posts are either.
Are you reluctant to continue to do the work to keep you and your website relevant in the search results? Once your site has been optimized you must continue your efforts beginning with blogging where you use the keyword phrases that your target market may use.  Then you need to continue doing the following…
Be sure you provide social media share icons on your individual blog posts.
Give visitors a reason to give you their email address and continue to engage with them through email.
Use video to get your message across and connect with your audience, using YouTube and other video sites.
Continue to repurpose content into other mediums to reach a broader market.
My point is it is not SEO and done, you must continue doing the work to continue to get the results.  There is no magic bullet and no easy way to the top.
Create content that others need and want and do it on a regular basis that is the roadmap to success.