If your product needs zero rework for each sale (and scales easily), many customers is the obvious way. If it requires a sales process (even if it's as simple as signing a contract), less customers (paying more) is the way.

Personally, I prefer the "less customers" approach. I find it much easier to pleas everyone and feel like I'm not "working for free" when "everyone" is a relativelly small group and the payback is still high