We've been without valuable analytics in iTunes Connect for so long it's easy to forget the wealth of information now available from Apple. This is a good guide on what's in there, what you might have missed, and how to use data like you App Store conversion rate to experiment with different marketing ideas.
"By monitoring your App Store Views closely, you can learn a great deal about ASO and what worked and what didn’t work."
Apple App Analytics 101
Too many 1 star reviews can kill your app. If you don't bother the user for a review, you won't get reviews. That can kill your app too. Amy sees both sides of this problem well and is experimenting with something less obtrusive in her app, UK Transport.
Please rate my app by Amy Worrall