Which then begs the question if I was the user: "Am I being served an ad or is ChatGPT taking in a bunch of product information and giving me an objective answer to what I'm looking for?"

This would create a ton of hesitation to use this for product recommendations if I knew ChatGPT wasn't using its extensive input for products and reviews and coming back with an objective answer for me.

I guess at this point would we even know the difference? Is it possible this is already happening?

It's what Google does today and they're the 4th most valuable company in the world.