Hi Sally,
We've performed quite a few NPS campaigns for various B2B software companies and we generally see fairly high response rates, sometimes as high as 40% or more. I think often times it comes down to how you're presenting the survey/questionnaire.
For us, short and simple with just a bit of context always works best. We also don't allow for anything outside of the primary recommend question plus the open-ended follow-up as is recommended. One other thing we do for our clients is embed the intial question right into the email that is sent which has improved response rates since they don't need to click out to a survey.
You might try experimenting a bit more with the delivery. Post-survey follow-ups (closing the loop) will also ensure previous respondents stay engaged as you come back around to them in the future.
Hope this helps.
Regards,
Chad Keck
CEO, Promoter.io
