Old post here about customer service :: https://seedvc.blog/2013/10/07/a-startups-secret-weapon-customer-service/
I am reminded of this due to a tweet I saw today:
Bottom line is that performing amazing customer service is the best form of marketing ever.
You will retain customers which is cheaper than buying new ones and word of mouth will bring you new ones.
Plus you and your employees will feel better about what they do.