Amazon link vs brand's own affiliate program: rate vs conversion

Amazon link vs brand's own affiliate program: rate vs conversion
Many brands sold on Amazon also run direct programs (often via an affiliate network) at 8-15% vs Amazon's 1-3%. But:
— Amazon: 1-3% rate, but ~3-5% conversion (native trust, Prime, one-click)
— Brand-direct: 10% rate, but ~1-1.5% conversion (new checkout, shipping friction, cart abandonment)
Math on a $50 product: Amazon 2% x 4% conv = $0.04/click. Brand 10% x 1.2% conv = $0.06/click. Close — and it flips by product.
So what: don't assume the higher rate wins. Run both as parallel SubID-tagged links on the same page for 1,000 clicks each, then keep the higher-EPC link. Conversion usually eats the rate advantage.