Usage-based pricing is somewhat less common among SaaS businesses— it's mainly used by telecommunications companies and IT services.

It makes it easier for small companies to get started with your product while avoiding the high upfront fees charged by some subscription companies. On the other end of the scale, it also accounts for additional costs incurred by heavy users, charging them fairly based on the extra time and resources they're consuming.

Charging based on usage does, however, make it much harder to predict revenue, since billing can vary dramatically each month.

Fixed pricing stays simple: a single product, a fixed set of features, and a fixed price per month.

Flat-rate pricing is easier to communicate and easier to sell. Adding valuable features? Raise your rate. Additional products? The fixed price goes on top of your base fixed rate.

But w...