Having ecommerce enable small and large clients since 1997 with many still online taking orders from SE generated traffic you'll need to use every good white hat SEO practice mentioned here. All the Google SERP slapping going on starting with last years Panda update is to eliminate lousy customer facing pages from getting on page 1-3. Google has 30,000 human doing nothing but ranking SERP listings for popular article and product buying keywords. The human ranking are passed to the Google Algo programmers to tweek those they think aren't deserving of page one listings. It's all about the customer (Google's searcher) satisfaction and eliminating SEO page rank trickery, Paid Adword click traps getting in organic listings, adware/spyware/web bug drive-by installs. I sometimes eat lunch with GooglePlex staffers and grunts in Ann Arbor....
As pointed out here organize everything to engage a shopper as #1 object of your page is to optomize the customer facing content and images on your keyword landing page. Seldom does a deep link product page get traffic from more then 4 keyword combos. Category pages are more general and might get SERP traffic form 6-8 keywords. Google & it's employees all rate a pages staying on page one based upon the Google Searchers reaction to the landing page.. 1. Length of time on page and no immediate exit. 2. Deeper browsing & more clicks within the domain add to the time spent from a Google SERP click. 3. If landing page is detected as a Merchant page ( working add to cart button ) you get to excape the new site/page Google sandbox as they consider merchants as a responsible authority class fuduciary liable for order fulfillment.
So organize you page keywords without stuffing them and write the painful extensive text about your specific product or service and treat every product page as a first impression home page... Google will! Engage your customer and pray they stay a long time on every click to your domain. If so ... your page one material regardless of Google Algorythem changes.
Now I pleased to learn switching to Americommerce I can keep my clients hard earned page one SERP listings in place by keeping the same URL names with building out the same number of Americommerce pages... + new ones with SEO friendly .htm names. I'm just starting here bringing over clients like Holdup Suspender Company www.suspenders.com and my just launched Satellite sales site http://www.holdup-suspenders.com that escaped the Google new site sandbox.
Webmaster Mike Hyland
Image Marketing Services
St Clair Shores MI