IMO if an existing product is swinging between failed features and wild successes, chances are that it's being done based on luck (either good or bad), not any

IMO if an existing product is swinging between failed features and wild successes, chances are that it's being done based on luck (either good or bad), not any particularly great PM practise. Sure, startups and new products will either go gang busters or broke. But any decently mature product is almost always going for steady incremental improvement based on feedback and market shift. Now, I'm not saying they're achieving that... but that's what a decent PM should be aiming for.