After a conversion, only suggest companion products such as maintenance, extensions, and optional modules.
Do not recommend alternative products. You are risking to irritate and confuse your customers.
This issue is frequently underestimated by the people or teams in charge of product recommendations. There is nothing more irritating than getting, just a day after a pourcheses, a recommendation for a promo on a product that was more expensive than the one we selected.
For recommendations on how showing the best products reviews can improve your Conversion Rate take a look ta my eCommerce Tip #124: Leverage positive reviews to provide social proof and improve Conversion Rate.
Franco Folini lives and works in the eCommerce territory, a wild area between the Kingdom of Technology and the Kingdom of Marketing. He speaks fluently the language of both realms. For many years, Franco has been helping people bridge the divide and successfully collaborate.
If you want to find out more about Franco, visit his LinkedIn profile or send him an email folini[at]gmail.com