The different customer and prospect segments (low/mid/high value) are calculated by segmenting your Account Values and then dividing them into four quartiles.
Account values are either set in your integration, or they can be set in the account page manually.
Low-value customers are those who fall into the 1st quartile, Mid-value into the 2nd and 3rd quartiles, and High-value into the 4th quartile.
In other words:
If all of your values are the same, then they would technically all fall into the 1st quartile, and as a result would be classified as Low-value customers.