One way to achieve customer satisfaction and open the door to product loyalty is to force the buyer to make a choice, even if it remains private. The choice is: "would you rate this purchase/product/experiment positively or negatively?" If the customer decides on positive, then it's reasonable to expect they'll consider a social media share as an immediate outlet for their satisfaction. If the customer decides they've had a negative experience, then you need to immediately channel that away from public sharing and toward your problem-solving system.
Print can do that! Your customer won't be looking at a screen as they open your package. But a little piece of print can be right there, with all the immediacy needed.