Loyalty today is far more than just a sale. Loyalty is about a relationship. At the end of the day we still want to see a purchase however arriving that that destination can take many paths.
Have your service team hand the customer a loyalty/reward card or mail it to the customer physically or by email. When your sales team makes a customer satisfaction/upsale call have a reward code handy to provide to targeted customers.
Make this a production, emphasis how important the client is to you because they are.
For example a furnace company doing an install could offer free filters.
And automotive company fixing a transmission could offer free oil changes, free wind shield wipers or a coffee at the corner Tim Horton’s tied to social.