Ran affiliate tracking on spreadsheets for two years before making the switch. There's plenty of noise on this topic, but most takes miss where the actual pain hits. Here's what I found.
Up to 15 active affiliates - spreadsheets work fine. Commission calc is manual but doable, payouts are batched monthly, you know every partner by name. Anyone telling you to move to software at this stage is selling something.
15-30 affiliates - the grey zone. A well-structured sheet still holds, but you start feeling the pinch on commission accuracy, link generation, and partner onboarding. Some teams jump ship, others stay. Both are defensible.
30+ affiliates - dedicated tools start paying for themselves. Commission structures get complex enough that spreadsheet errors creep in, tracking breaks, and partners want self-service portals rather than emailing you for updates.
At the 30+ mark, we went with Refersion for tracking and partner portal, paired with Upfluence for the creator side - most of our partners came from influencer backgrounds. Impact would have been overkill, ShareASale's strengths didn't align, and PartnerStack wasn't built for ecom.
Here's the key insight: the breaking point isn't affiliate count alone - it's volume plus complexity. Fifty affiliates on a single flat rate are easier to manage than fifteen with custom tiers, performance bonuses, and exclusivity clauses. Look at total complexity, not just headcount.