The choice between customer acquisition and retention is a false choice. I recommend instead employing a diversified and balance customer lifecycle management approach with customer acquisition, onboarding, development and retention elements.
Customer Acquisition, Development and Retention are very connected and have many downstream and upstream implications. For example, many Customer Retention challenges are embedded in downstream poorly designed Customer Acquisition and Onboarding programs. Therefore, focusing on any one element and not the others can produce underwhelming results.