The verdict
For a small B2B team selling subscriptions, I'd pick FirstPromoter. The billing-based tracking is the right way to do this, and payouts and tax handling are in the same place.
If you sell physical products, run a shop, or want partners tied to deals in a CRM, pick Tapfiliate. It is also the better choice when you want several programme types, such as affiliates, ambassadors and resellers, from one account.
Before you sign, check the limits. Tapfiliate caps clicks and conversions on the entry plan, and its trial is short. FirstPromoter plans follow affiliate revenue and its trial is longer, with no card needed.