Often, we get so involved in the day to day grind of managing our sites, and concentrating on the latest, greatest techniques, SEO or otherwise, that we may overlook some very important aspects. Sometimes, we need to take a step back, and instead of looking at the details, we should instead focus on the big picture.
Is there something that your users would like to find on your site, but you haven't supplied them with it? Have you really given your users all the content they are seeking?
Have you become so focused on providing them with the best way to purchase your products, that you have forgotten to give them information on how to use those products? Or how to repair those products? Or what the differences between products may be?
Have you looked at your logs recently to see what searches are bringing visitors to your site? Quite possibly, a large number of users are finding your site only to discover that you don't have the content they expected to find. What do they do? They click that Back button and find another site listed in the search engine rankings. What if they HAD found the information they'd wanted? They would have stayed on your site which is right where you want them.
If you have a commercial site focused solely on the display of products and the ability to purchase products, you may be missing out on a huge amount of potential traffic. There are many ways a visitor can arrive at your site, and the more chances you give them for finding your site, the more likely you will get them there. Consider adding high-quality content such as how-to articles or product reviews and comparisons in a separate section of the site. Each of these articles (or blog posts if you choose to use a blog) could then include deep links back to relevant products on your site.
If the articles are truly high-quality, you will probably also gain the benefit of others wanting to link to them. And if you use RSS, you can gain backlinks that way as well.
So, take a moment today to sit back and broaden your vision of your site. Instead of thinking in terms of SEO details, think bigger in terms of SEO being a huge net capable of capturing visitors from a wide sea of interests.