When asked what eCommerce companies can do when they are facing out of stock situation, Google’s Matt Cutts said it all depends on the size of the website. He categorized the websites in 3 sections: small sites having tens of pages, medium sites with thousands of pages, and large sites with hundreds of thousands of pages or more.
Small eCommerce sites
Cutts said that the small sites that sells products such as handmade furniture should link the related products. This way, despite being disappointed, the customers would be able to browse through the other products. However, this doesn’t mean that the customers shouldn’t add a manufacturing time next to the items that are out of stock.
Medium eCommerce sites
When medium-sized eCommerce sites face out-of-the-stock situation, they should display “404-page not found” error, unless they know the date the products will be back in inventory. If the eCommerce merchant is aware about the inventory replenishment date, they should let the visitors know about it and offer them an option for late delivery.
Large eCommerce sites
When it comes to huge eCommerce websites such as Craiglist, merchants should set the date the page will expire using the meta tag, unavailable_after tag. Once this information is added, Google will remove the page from the search results page within a day. And when the product is added back, the merchant can immediately set when that product page will expire based on an auction date or a go-stale date.