Would be interesting to see a similar study for B2B - I can only hope that it's a little better.
Surprisingly few companies seem to close the feedback loop which is why we've made it a central feature in our product. This is then reflected in a much higher response rate that our clients are seeing compared to before or if compared to average industry response rates.
If your clients get the feeling that the feedback they provide is actually being read and reacted to they will be happy to provide feedback on their experience. This is especially true in B2B.