What Percentage of Small Business Contacts Remain Valid After 12 Months? | InfoGlobalData

ZeroBounce reported a 28% decay rate in 2024, falling to 23% in 2025. The 2025 result was lower than the previous year but still represented nearly one-quarter of the email data analyzed. (ZeroBounce)

This is important for marketers because a one-year refresh cycle can leave a significant portion of an older database exposed to deterioration.

Consider a hypothetical list of 10,000 contacts:

• At a 23% decay rate, about 2,300 records would fall into the measured decay category.
• Approximately 7,700 records would remain outside that category.
• But the 7,700 should not automatically be called verified or deliverable, because the study's decay figure is not equivalent to a fresh verification test.

The example illustrates why marketers should avoid making assumptions based solely on list age.

A six-month-old list is not necessarily accurate, and a 12-month-old list is not necessarily unusable. Verification provides a much stronger answer than age alone.

Why Data Quality Matters More Than List Size

A large database can create an illusion of marketing strength.

Suppose one company has 50,000 poorly maintained contacts while another has 10,000 recently verified and appropriately segmented records. The second database may be more useful for actual prospecting.

Salesforce's State of Data and Analytics, 2nd Edition found that 84% of data and analytics leaders believe their data strategies need an overhaul to successfully support AI initiatives. Only 47% rated data quality as fully prepared for AI in 2025. (Salesforce)

Although this research is broader than email marketing, the underlying lesson applies directly to contact databases: automation does not eliminate the consequences of bad data.