For products, I'll find suggestions from reddit, signal it with the conversational quality, then corroborate it against other places that reviews may exists like forums, youtube, facebook, instagram, etc.

Usually, a great product will have enough activity surrounding it that it's difficult to fake with bots. Especially, Instagram profiles with <1000 followers + non-seo-optimized stories/posts raving about something signals that the the <joy-from-product> is organic rather than manufactured.

I think the strongest signal for legitimate IG accounts is the ephemeral nature of the 24-hour IG stories. I suppose someone enterprising could auto-build hundreds of personas that post stories daily, but a random profile with stories posting activism, their morning latte art, a selfie with some friends seems doesn't fit in the ROI of a scalable marketing strategy across a ton of accounts. Maybe I could be wrong?