The comment section under a running ad is the most honest focus group you'll ever have access to. Here's how I read it and turn what I find into creative that actually converts.
At a US-based DTC home and lifestyle brand running $300k–$600k a month on Meta, we were running somewhere between 30 and 50 new creatives a week depending on the season. At that volume you develop systems for finding angles, and one of the better ones I stumbled into wasn't a tool or a framework — it was just reading the comments more carefully.
Comments under a live ad are different from reviews. Reviews are written when someone already made up their mind — either happy enough to say something or frustrated enough to complain. Comments happen mid-decision. Someone scrolling, stopping, half-persuaded, and then typing out exactly what's holding them back. That hesitation is incredibly useful creative intelligence.
The other thing about comments is that they're self-selecting by engagement. If fifty people asked the same question, that question is probably the most common objection in the room, not just an edge case. And if someone left a negative comment that generated thirty replies, the emotional core of that exchange is almost certainly something your next ad needs to address.
You can spend hours on customer interviews, review mining, and competitor research — and you should. But the comments under your running ads are real-time, unprompted, and free. Ignoring them is leaving a brief on the table.
Not every comment is useful. A lot of it is noise — people tagging friends, one-word reactions, arguments between strangers. What you're looking for falls into three categories: the objection, the question, and the controversy. Each one maps directly to a different type of ad creative, and each one tells you something the brief you wrote yourself probably missed.
At the brand we sold a lot of products where the category skepticism was higher than the product deserved — gadgets and home items where buyers had been burned by similar things before. The comment section became one of the first places I'd look when a product was converting well enough to scale but had hit a ceiling. Here's how the process played out for a home organization product — a wall-mounted storage system in the $45–65 range. The specifics are representative; the pattern is exactly how it worked.
This doesn't need to be elaborate. I've done it in twenty minutes with a notepad and it's produced briefs I couldn't have written from scratch. The discipline is in what you're looking for, not in how long you spend looking.