As VOC is very important, what is more important is who is being asked and who is responding. Too often, VOC is weighed too heavily by what can be termed as "Tier 1" or "Tier 2" customers. A lot of feedback is gained, but not at the level that will provide real insight to the needs and requirements.
At one time, surveys were sent out that were well segregated into four categories: 1) Corporate level, 2) Decision Makers, 3) Influencers, and 4) Users.
You would be surprised how dis-jointed 1 and 2 are from 3 and 4. The problem is, we fulfill the requests (new products, new services, etc) of 1 and 2, but then field the (dis-satisfaction) calls from 3 and 4.