When and where appropriate, injecting humor into your customer experience can surprise customers and/or lighten situations. Being funny without being offensive is a delicate balance, but if your brand and your people can pull it off, create the opportunity for humor.
Southwest Airlines flight attendants are famous for their entertaining in-flight announcements. CD Baby sends hysterical auto emails after every CD purchase. Check out the dozens of great examples of humor in practice, and you'll find the right degree for your brand.