QA comes in many forms, from the developer who tests her own code, to the testing gurus who work with automated testing tools. Many vendors and groups have recognized testing as an integral part of the development and maintenance process and have developed certifications to standardize and demonstrate knowledge of the QA process and testing tools.
Taking a certification exam, can help you differentiate yourself from peers , broaden your employment chances and result in higher remuneration.
Employers too benefit, since a certification acts as a skills verification tool and improves the staff's ability to quickly complete on-the-job tasks.