Suggestions to customers for products they may be interested in based on products they’ve already bought or viewed online. For example, if a customer bought the same tank top in 3 colors, there’s a good chance they’ll like the same tank in a new color. Personalized product recommendations, which mathematical calculations called algorithms determine on the back end, are a key feature of websites for cross-selling and upselling.

The 3 Things To Avoid When Emailing Your List
When you decide to have an opt-in list, it is not just a matter of sending your subscribers your promotional newsletters or catalogs.