This is true of regular advertising too: many people think they're immune to it. Corporations wouldn't spend billions if it wasn't effective.

That being said, I tend to agree with you in the sense that I never buy the obscure products that are recommended to me on FB/Google.

On the other hand, I think paying YouTubers to promote products is super effective. People are extremely receptive to influencers recommending products, esp. when it doesn't seem like advertising.