"If you believe you do not have the budget to do both you are missing an opportunity to improve on your bottom line, CX data tells you what your customers’ perceptions are of the services you are marketing and providing, whereas Mystery Shopping data is a reality check of what is actually being delivered toward your brand promises.
For the remainder of this blog I will be going into more detail on why you should conduct a mystery shopping program in tandem with your CX program."
https://www.business2community.com/customer-experience/cx-mystery-shopping-great-questions-to-consider-02174996/