Short answer: Partnero is worth it when the job it does — affiliate program software — is a live gap in your operation, and not before. Here's the honest calculus.
What you're actually paying for
Partnero is affiliate program software. The value case rests on that one job: if it's currently done manually, done badly, or not done, the tool typically pays for itself. If the job doesn't exist in your business yet, no price is cheap enough.
When it's worth it
You can point at a cost — hours spent, revenue leaked, orders missed — that the tool removes. Run the maths against the plan you'd actually buy, not the cheapest one.
When it isn't
You're pre-launch, the category is a nice-to-have for your model, or a tool you already pay for covers 80% of the job. See alternatives before committing.