Incorrect schema implementation can nullify benefits or result in penalties. One common mistake is marking up content that users cannot see. Hidden or misleading schema violates guidelines.

Using the wrong schema type is another frequent issue. For example, applying product schema to informational pages creates confusion and reduces eligibility for rich results.

Outdated or inconsistent markup also causes problems. Content updates must be reflected in structured data to maintain accuracy.

Overloading pages with unnecessary schema can dilute clarity. Schema should enhance understanding, not complicate it.

Avoiding these mistakes ensures structured data improves visibility and trust rather than creating compliance risks.