I can only speak to how we do business at Relay FM. Sponsors cannot but any endorsement; it’s simply not for sale. If we, or any other Relay hosts endorse a product in an ad, it’s because we genuinely do like it.
As far as sponsors’ products making it into content — once again that’s not for sale. If a sponsor’s product comes up in conversation, it’s of the hosts’ own doing. It’s why we go out of our way to disclose a sponsor when they come up in conversation.