The need for Farming
As stated already, it is far most costly to hunt than to farm. This though isn’t the only reason to look after your customers. Existing customers provide regular income, possibly reference sites, referrals and relationships.
Loyal customers are the backbone of most businesses, just look at all of the incentive schemes on offer aimed at encouraging you to stay with the same supermarket, airline, coffee shop or whatever. Whilst some get it right, many get it wrong. Take for example insurance, rather than encourage loyalty, existing customers are often penalised with higher renewal premiums than new customers.