Be aware that podcasters and other online "influencers" (including real experts) often earn a significant portion of their income from product endorsements. That might not be the case here, but it's always important to keep a healthy skepticism.

In addition to selling directly, the sponsors hope people will echo the influencer's endorsement in their own social media posts. I know from an advertising acquaintance that that's called "earned media," and it's highly prized, not only because it's free, but because people see it coming from someone they might already know and trust, rather than from a corporation or online personality.