Fomo championed what is now called PLG (product-led growth) by doing exactly what you've hinted at -- listening to customers.
specifically this happened during long, back and forth conversations with recent signups who submitted support tickets. i think our casual attitude in these exchanges (no canned response) made customers feel comfortable "dreaming," which in practical terms means pitching feature requests. we received 20-40 tickets /day.
since i (founder) had an eye on the customer service inbox for years, starting as the sole sole support rep, i had the opportunity to chat with 100s of customers directly and later read 1,000s of exchanges as the support team grew to 3 people. i don't think i ever went more than a couple days without getting involved on a ticket, for better or worse.
so that's the context. but the difficult part isn't "listening to customers" so much as deciding which customers to ignore. a lot of marketers use their ICP (ideal customer profile) to create these boundaries, whereas we made the call a bit more qualitatively, essentially based on the customer's vibe. do they overuse exclamation marks? threaten credit chargebacks if we don't do x-y-z?
polite customer requests were expedited (often i'd build the entire feature, then reply "great idea, this is now live!"), rude or low-quality customers (ex: zero-sale brand new Shopify stores) were delayed or denied.
in some cases we built feature requests for a nominal fee (say $100-250), or by requiring the customer to upgrade to our annual plan. asking customers to have skin in the game is a simple but effective way to prioritize the never-ending list of dev tasks.
of course, underscoring all of this was taste, conviction, and saying "no" more times than we ever said yes. i can't count the number of times someone requested tools to input fake data, or generate questionable scarcity with countdown timers, or make their pre-recorded webinar look like a live sales event. no, no, and no were the answers.