Easy way to "create and maintain a B2C relationship" is email.
Email marketing is a good part of a long term business strategy.
There are different email promotion types.
Good email promotion type is a returning customer freebie. Returning customer freebies help to create a special bond between the customer and the business. These kind of discounts get the client closer with the business and help to keep the client buying with the business and not going elsewhere.
I myself, am subscribed to few awesome businesses and I love getting freebies from them in the email. Sometimes it's a new song or a new video. It's a bit special and fun.
I recommend to implement a freebie strategy by email for loyal clients to any business.