Change of Sponsor/Champion can be a major source of churn. This is when the financial buyer of your service leaves the company or is promoted into another area of the business. How big this issue will be for your company varies widely by industry norms of leadership retention in the markets you serve.
Root cause of churn related to Change of champion is mostly likely either Lack of adoption or Didn’t realize ROI.
The reason is simple. A new stakeholder is going to have their own biases and agenda, so as an incumbent, you’re already at a disadvantage. However, when a the new sponsor sees productive usage of your product resulting in tangible ROI, chances are much better you can retain the business.