Annual decay = 5% → retention = 95% = 0.95 - Deep Underground Poetry

Understanding the Context

What is Annual Decay at 5%?

Annual decay of 5% refers to a consistent decline in retention where, each year, approximately 5% of your existing users or customers stop engaging or renewing their membership. Put simply, if you started with 100% retention, after one year, only 95% remains active or retained.

Mathematically, this decay is modeled as:
Retention after 1 year = 100% × (1 – 0.05) = 95% = 0.95

This model presumes a constant decay rate over time, typical in subscription services, customer loyalty programs, and user-engagement platforms.

Key Insights

How Does 5% Decay Impact Retention?

A 5% annual decay may sound small, but over multiple years, its compound effect becomes significant. For example:

| Year | Retention Rate | Cumulative Retention |
|-------|----------------|----------------------|
| 0 | 100% (1.00) | 1.000 |
| 1 | 95% (0.95) | 0.950 |
| 2 | 95% (0.95) | 0.9025 |
| 3 | 95% (0.95) | 0.8574 |

As shown, retention drops steadily — a 5% yearly drop means that retaining customers gets harder each year. A retention rate of 0.95 reflects a strong, consistent performance but still signals a meaningful struggle to maintain user engagement.

Final Thoughts

Why Retention Retention = 0.95 Matters

Retaining users matters more than acquiring new ones—studies show customer retention carries higher lifetime value and lower cost. A retention factor of 0.95 implies:

• High efficiency in customer experience: Only a small 5% slip-off indicates that your product or service delivers compelling ongoing value.
  
• Predictable revenue streams: Consistent retention supports stable cash flow and financial forecasting.
  
• Benchmark for improvement: Tracking 0.95 retention helps identify weaknesses early, prompting proactive engagement strategies.

Common Causes of a 5% Annual Decay