In Personal Merchandising, there are two standard personal components available: Last viewed and Previously bought. Both components are personal and based on the viewing and buying behavior of a customer within a session and over multiple sessions. We will shed some light on both components and how they work precisely.

It goes for both components, that viewed or purchased products are measured in the implemented tracking script.
Read more about the implementation and process of these tracking scripts here.

Last viewed

The Last viewed component is the actual last viewed product of the customer within the concerned category. This component can change in real-time throughout the session based on a customer's viewing behavior. This is remembered by the system, even when the current session is ended and the customer returns later.

Previously bought

All previously bought items are assigned a weight after purchase, that diminishes in time. The default half-life is 7 days. That means that we assume that a product that is not purchased after 7 days, becomes less relevant than products that are purchased within those 7 days. This half-life can be changed but is 7 days by default. This determines the sorting of previously bought items, in case you want to show an extensive list of these in your shop.

An example to further clarify this:

A customer buys three bottles of wine and a block of cheese today, then the wine will be on top with a weight of 3. If this customer buys a bag of chips within 7 days, the wine will still be on top, as the customer bought three of those, and only one block of cheese. After 7 days, the weight of the wine is halved, and will be 1,5. If another bag of chips is bought, or two other, similar items, then that product will appear on top.