The Wirecutter (now part of NY Times) is another that doesn't accept freebie products, if I recall.
They do use affiliate links, so they have incentive to want you to buy _something_, but no incentive to give any particular brand or model a biased review.
I still can't believe people actually click on affiliate/tracking links. I get things based on Wirecutter reviews occasionally, but I always go to the product separately so it's not tracked.
As long as it's a generic referral program (Amazon?) in general I find it at least somewhat ok - I can see how they're getting paid, and I can assume (maybe?) they aren't getting a special kickback to sell that particular product over another one at Amazon or whatever.
When it's seller specific affiliate programs? It's all just spam basically.
They do use affiliate links, so they have incentive to want you to buy _something_, but no incentive to give any particular brand or model a biased review.