I second what Jaz Cuevassays about UserEvidence. I implemented them at my last company and got results as soon as I sent the first survey. They are my go to tool now so check them out if you can. Survey responses can help all teams with customer proof and can be sent throughout the customer lifecycle. It's also a great way to get reviews trickling in and find customers who want to do all kinds of advocacy including case studies. I'd love to share my experience with them and customer advocacy in general if you'd ever like to chat.