At the margin, it's very hard to tell the difference between advertisements and other media. Today I listened to an enjoyable podcast with 5 speakers, 2 of who

At the margin, it's very hard to tell the difference between advertisements and other media. Today I listened to an enjoyable podcast with 5 speakers, 2 of whom are employed by the same company. During the episode, they discussed a product that those 2 worked on. Was this an advertisement? I think any ban like that would have a "I know it when I see it" standard, which isn't wonderful.