This approach is particularly successful for managing requirements and functional tests on large-scale projects of significant domain and organisational complexity.
[1] A key aspect of specification by example is creating a single source of truth about required changes from all perspectives.
When business analysts work on their own documents, software developers maintain their own documentation and testers maintain a separate set of functional tests, software delivery effectiveness is significantly reduced by the need to constantly coordinate and synchronise those different versions of truth.
As there is only one source of truth about the functionality, there is no need for coordination, translation and interpretation of knowledge inside the delivery cycle.
When applied to required changes, a refined set of examples is effectively a specification and a business-oriented test for acceptance of software functionality.
[3] Example Mapping is a simple technique that can steer the conversation and derive Acceptance criteria in a short time.
There are documented usages of this approach in domains including investment banking, financial trading, insurance, airline ticket reservation, online gaming and price comparison.