Amazon + Chewy Marketplace + Walmart channel reach, when do you play and when do you skip?

Channel strategy for pet brands is a margin question, not a reach question.

• Amazon Subscribe & Save, almost always worth it. 100M+ Prime members on auto-ship. Cannibalization of your DTC sub is real (~15-25% of new SKU launches start on Amazon and migrate to DTC). Margin: 15% Amazon referral + 10% Subscribe & Save discount you fund = ~25% lower contribution vs DTC. Worth it for top-of-funnel reach.
• Chewy Marketplace, harder call. Chewy owns the customer; you ship fulfillment via Chewy CFS (Chewy Fulfillment Services) or your own warehouse. Margin: 10-15% Chewy referral. Brand-equity risk: if you’re a premium / boutique brand, Chewy positions you next to Purina, not always the right look. Use for clearance / older formulas or when you have a brand-niche Chewy is amplifying.
• Walmart Marketplace, smaller but growing fast in pet. Margin: 6-15% referral. Worth piloting at $5M+ if you have inventory headroom.
• Petco Pivot Network, for pro-channel / veterinary brands only.

Tech side: Channable, Feedonomics, or Codisto syncs Magento → channels. Magento stays the OMS-of-record; channel orders ingest back via API. Inventory is shared from Magento stock; oversells happen at the channel side when feeds lag, build a 10% inventory buffer per channel.

What I’d advise a $2M, $5M pet brand: Magento DTC first, Amazon Subscribe & Save second, Chewy third (and only if your brand fits). Don’t start with channels; start with first-party data.