The following sites and resources offer a lot of great information on SEO and marketing, and will help you drive more traffic to your eCommerce site. You can also browse all the eCommerceFuel SEO and Marketing articles.
ThinkTraffic.net – A site dedicated to increasing the traffic and audience of your website, eCommerce store or blog. I’m a regular reader, and they produce a lot of quality, useful content.
SEOMoz.org – In my opinion, the best SEO community online. Their blog is extremely valuable, and they offer a vibrant forum to interact with and ask questions. Their Pro Tools require a subscription, but are definitely worthwhile if you’re serious about getting the most out of your SEO campaigns.
Mixergy.com – While his site is not focused exclusively on traffic, Andrew Warner of Mixergy interviews numerous entrepreneurs to learn how they became successful. In the process, you’ll learn a great deal about marketing and building traction for early-stage companies.
KISSMetrics Blog – The KissMetrics blog consistently produces highly actionable analytics, marketing and conversion articles.
QuickSprout.com – Written by KissMetrics founder Neil Patel, this blog has more of a marketing and SEO focus and also consistently has top-notch material.