So much of retention is about delighting your users through an incredible experience. One way to enrich their experience is to surprise them.
You can send hand-written notes to new customers or deliver unexpected freebies. If you want to really “wow” people, take the time to learn about them. This approach, of course, is not scalable, but you might find great opportunities to delight customers, like in the beef jerky story shared by Gregory Ciotti.
While this tactic can be a nice way to welcome a new customer, you should never stop selling to existing customers. A quick surprise can remind old customers that they’re still greatly valued by your company, and extend their lifetime with your products.