ortelius, I would like to give you some suggestions.
Now if you know other people with websites, do not post a banner, but ask or pay for them to host a small blurb about a product that you sell, and link it to your site. This does 2 things, first and foremost it helps your site, and second it helps theirs, also. You will see websites doing this more often in the future, and many are now, with pages of blurbs about other websites that sell any type of products.
No iframes, or java content. Just strict html or xhtml for your seo dollar. You are better off with search results doing it this way, and so is the webmaster of the page that lets you do it. This expands your keyword hit for your site and theirs.
You need to link to other sites with information about the product. If you sell gears and sprockets link it to sites that review them and why yours is the best. (Or worst even).
The best links you can have are companies that are successful and well known. Magazines are great for this that write content about products such is Consumer Reports or other magazines and websites that review products. (Even if the website requires a subscription to read about the product, which is even better).
You may find listings of your products coming up under a search result of Consumer Reports. It may not be at the top of the search, but maybe on the first page.
Another suggestion is using Youtube with your domain name if it is available for your youtube page. This will also help. These are just suggestions that I used when I owned my store. They will work and work well, and it will boost your rankings.
Many people confuse advertising and SEO is one of the same, but they are entirely different. SEO is only for people that are impulse buyers for the most part. They search for a product and if you are number one at the top of the page they will buy it, but most people will look and see if they can find a good deal through a reputable company for a good price, that part is done through advertising.
Most people do not understand why Google is changing its way it ranks websites, but really it is only common sense why they are in my opinion. Me, myself and I are in a good situation. This is because I only need to advertise the name of my domain, in which you can do a Google search for my username here and it will be on the top, and then Google the name on the heading (Title page name) for that and see what happens. I am afraid of using too much seo because I may get sand boxed. What would you do?