You can exempt a product from affiliate sharing by one of these methods:
- Enable its product-specific Hop Link and set a 0% product-specific percentage;
- Leave your Common affiliate Share set at 0% even if you enable your Common Hop Link, and then just enable the product-specific Hop Link and specify a product-specific share percentage only for those products that should grant a commission.
Eventually we plan to make the product-specific share % independent of enabling a product-specific hop link (since it clearly doesn't make much sense to offer a specific link for a product that grants no commission), but currently things work as explained above.
That said, we generally recommend granting at least some nominal commission on every product if you're going to have an affiliate program at all, since affiliate-referred sales typically would not have happened at all without their referral, so they deserve some compensation for that. This will also minimize the potential for confusion and complaints when affiliates get notified of a sale they referred which granted $0 commission on a product with 0% share.
You may also wish to download your affiliate list from Seller Admin > View/Edit Affiliates, so you can email them personally to bring to their attention any changes to your affiliate program.