[InclinedPlane]

Falcon 1 had several customers, but it wasn't really cost competitive and they ended up with enough investments to develop the Falcon 9, which would be far more lucrative for them. How commercially viable the Firefly will be is utterly dependent on the cost. Given the simplicity of the design and the alleged ability to mass produce them, they might be able to get the price point low enough to be commercially viable.

Given that the satellites they are proposing to fly are built on budgets in the single millions of dollars, I think they are aware of what their costs need to be and wouldn't be doing this unless they thought they could hit those cost figures.