Do you measure how many out of stock page views (i.e. out of stock products which are being viewed by your visitors) you receive per day?
Consider shoppers who search for a specific product on Google, find you on on the search results page or an ad, click on it, arrive to your site only to discover that the product is out of stock. This is a disappointing experience for the shopper and a missed opportunity for your business.
So what can you do about it?
1. Probably the best thing you can do is show alternative product recommendations
at very prominent position in the product page (above the fold is highly recommended). So when people arrive to an out of stock product page they immediately see the alternatives and chances are your bounce rate will come down.
2. Another action you can take is to allow shoppers to get notifications when the product is back in stock. By doing this you engage customers and build up your permission based marketing database at the same time
3. Consider offering a coupon for first time visitors who landed on an out of stock page but purchased a similar product during the same session