Michael Gray tells us how to handle expired product pages, as well as those appearing on classified or auction site. He runs through what to do ig a product becomes temporarily out of stock,
discontinued, or replaced or updated by another product.
He also explains why you would want to use a 301 redirect code for the product or auction page instead of letting it expire and issuing
a 404 not found error message: Web sites only have a certain amount of inbound link equity, so the danger of leaving up expired products or auctions can rob the site of authority.
Read the whole story at Graywolf's SEO Blog »