Over the long-term, you want to grow the number of your above-average customers so they make up a larger part of your customer base.
You should absolutely continue to grow your customer base as a whole through customer acquisition. You just want to accumulate more above-average customers as you go.
There is no best number of above-average customers. What is best for one store might not apply to another.
Ideally you want it high and to be growing over-time. A good segmenting system like Repeat Customer Insights should keep track of it month by month for you.
Eric Davis
Go in-depth into your customer behavior to find more revenue
If you haven't installed Repeat Customer Insights yet, it's an easy way to get a detailed look at your customer behavior.