You can include your best selling products into a number of different email triggers. Here's an example of including your best-sellers into a winback email:
You can also send out an email earlier in the post-purchase sequence recommending some of your best-sellers.
In order to include best seller content in an email, just use
into your email content. It will only show best sellers that the customer has not already purchased.
You can also configured the number of days back that you want to look at best seller data using this configurable field: