This blog post by Kevin Sterneckert addresses the massive disconnect for many retailers.
Points discussed include:
The Ghost of Inventory Received and Posted Data – Consider this question, do you audit every item ordered to assure that all items are available for purchase?
The Ghost of Competitive Pricing and On-Site Search – Retailers should maintain a constant handle on what the competition is doing to quickly pinpoint the biggest disparities and maintain a positive sell-through speed.
The Ghost of External and Internal Exposure – With thousands or even millions of SKUs that can change daily, properly displaying and optimizing each SKU on the site can also be an overwhelming task. Is every product on your web site and ready for purchase? Are the landing pages correct, and are the product descriptions and image quality accurate?