Long-Term Analytics: 25-Month Data Retention Without Consent

Understanding long-term user behavior is crucial for business growth, but traditional analytics platforms face a critical limitation: GDPR requires deleting data after consent expires, typically forcing 6-13 month retention limits. Sealmetrics solves this with cookieless tracking that enables 25-month data retention without requiring user consent.

Key Takeaways

• 25-month retention without consent: Sealmetrics stores analytics data for over 2 years under GDPR Article 6(1)(f) legitimate interest
• No consent expiration risk: Unlike cookie-based analytics, your data won't be deleted when consent expires
• Complete historical analysis: Track seasonal trends, year-over-year growth, and long-term user behavior
• GDPR compliant by design: Cookieless tracking with zero IP storage meets data minimization requirements

The Data Retention Problem in Traditional Analytics

Most analytics platforms face a fundamental challenge with GDPR compliance: cookie consent expires, and when it does, you must delete all associated data.

Why Cookie-Based Analytics Lose Historical Data

Google Analytics and similar cookie-based platforms require user consent under GDPR Article 5(3) of the ePrivacy Directive. This creates several problems:

1. Consent expires after 6-13 months (depending on implementation)
2. Data deletion is mandatory when consent expires or is withdrawn
3. Historical analysis becomes impossible beyond the consent window
4. Year-over-year comparisons fail because data older than consent period must be deleted

According to CNIL guidelines from 2024, cookie-based analytics platforms must implement consent expiration and data deletion mechanisms. This means businesses lose valuable historical insights simply because the legal basis (consent) expires.

The Business Impact of Short Data Retention

Limited data retention affects critical business decisions:

• Seasonal analysis: Can't compare Q4 2023 to Q4 2024 if consent expired
• Customer lifecycle: Incomplete view of customer journey beyond consent period
• Attribution modeling: Can't track conversions that occur 12+ months after first visit
• Trend identification: Missing long-term patterns that only emerge over years
• ROI calculation: Incomplete data for marketing channels with long conversion cycles

In B2B SaaS, where sales cycles often exceed 6 months, this data retention limitation can cripple analytics entirely.

How Sealmetrics Enables 25-Month Data Retention

Sealmetrics operates under GDPR Article 6(1)(f) - legitimate interest rather than consent, fundamentally changing the data retention equation.

The Legal Basis: Legitimate Interest

Under GDPR Article 6(1)(f), processing is lawful when:

"Processing is necessary for the purposes of the legitimate interests pursued by the controller or by a third party, except where such interests are overridden by the interests or fundamental rights and freedoms of the data subject."

Sealmetrics qualifies for legitimate interest because:

1. No personal data collection: We don't store IP addresses, fingerprints, or cross-site identifiers
2. Session-based tracking: Each visit generates a unique, temporary identifier
3. Data minimization: Only aggregate behavioral data, no individual profiles
4. Transparent processing: Clear privacy policy explains data usage

As confirmed by CNIL's 2020 guidance, cookieless analytics that doesn't create persistent user profiles can operate under legitimate interest, not requiring consent.

Technical Implementation: Zero Personal Data

Unlike competitors that hash or pseudonymize IP addresses, Sealmetrics uses a dual tracking approach:

Session-Based Tracking:

• Each visit = unique Session-ID
• Session-ID expires after 30 minutes of inactivity
• No cross-session tracking by default
• Zero personal data in the identifier

Isolated Hit Recording:

• Each pageview = independent data point
• No IP address storage (not even hashed)
• No device fingerprinting
• Aggregate patterns only

This architecture means the data we retain for 25 months contains zero personal identifiers, making it fundamentally different from cookie-based systems that must delete data when consent expires.

Why 25 Months Specifically?

The 25-month retention period is strategically chosen:

1. Two full years of data: Enables year-over-year comparisons
2. Plus one quarter buffer: Covers full seasonal cycles
3. GDPR proportionality: Long enough for legitimate business needs, not excessive
4. CNIL compliance: Within reasonable retention for aggregated analytics data

After 25 months, data is automatically purged from Sealmetrics systems. This automatic deletion demonstrates compliance with GDPR's storage limitation principle while providing maximum analytical value.

Comparison: Data Retention Across Analytics Platforms

Here's how long-term analytics capabilities compare across major platforms:

Feature	Google Analytics	Plausible	Matomo	Sealmetrics
Legal Basis	Consent (Article 6(1)(a))	Legitimate Interest	Legitimate Interest	Legitimate Interest
Requires Consent Banner	Yes	No	Depends	No
Maximum Retention (With Consent)	14-26 months	Unlimited	Unlimited	25 months
Maximum Retention (Without Consent)	0 months	26 months	26 months	25 months
Data Deletion on Consent Withdrawal	Required	Not required	Not required	Not required
Stores IP Addresses	Yes	Hashed	Hashed	Zero IPs
Cross-Session Tracking	Yes (cookies)	Optional	Optional	Session-only
Personal Data Risk	High	Medium	Medium	Zero
Year-Over-Year Analysis	If consent maintained	Yes	Yes	Yes
Setup Complexity	High (consent mgmt)	Low	Medium	2 minutes

Key Insight: Sealmetrics is the only platform that combines zero IP storage with 25-month retention, providing long-term analytics without any personal data collection.

Implementation Guide: Enabling Long-Term Analytics

Setting up Sealmetrics for 25-month data retention takes less than 5 minutes.

Step 1: Install Tracking Script

Add the Sealmetrics script to your site:

<script defer src="https://cdn.sealmetrics.com/v1/track.js" 
        data-site-id="YOUR_SITE_ID">
</script>

That's it. No consent banner configuration needed.

Step 2: Configure Data Retention (Optional)

By default, Sealmetrics retains data for 25 months. If you need a shorter period for specific compliance requirements:

// Custom retention (in months)
window.sealmetrics = window.sealmetrics || {};
window.sealmetrics.dataRetention = 18; // Custom: 18 months

However, since Sealmetrics doesn't collect personal data, there's typically no reason to reduce the default 25-month retention.

Step 3: Access Historical Data

Query data from the full 25-month period via API or dashboard:

// API example: Get pageviews for last 2 years
fetch('https://api.sealmetrics.com/v1/stats/pageviews', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    site_id: 'YOUR_SITE_ID',
    date_from: '2022-06-01',
    date_to: '2024-06-01',
    period: 'month'
  })
})
.then(response => response.json())
.then(data => console.log('24-month pageview trend:', data));

Step 4: Verify Compliance

Check your privacy policy includes:

We use Sealmetrics, a cookieless analytics platform, to understand 
how visitors use our website. Sealmetrics:
- Does not use cookies or require consent banners
- Does not store IP addresses or personal identifiers
- Retains aggregated analytics data for 25 months
- Operates under legitimate interest (GDPR Article 6(1)(f))

No personal data is collected. For more: https://sealmetrics.com/privacy

Use Cases: When Long-Term Analytics Matter

Seasonal Business Analysis

E-commerce sites with strong seasonal patterns need multi-year data:

Q4 2022 revenue: €150,000
Q4 2023 revenue: €180,000 (+20%)
Q4 2024 revenue: €225,000 (+25%)

With consent-based analytics: Can't compare 2022 data if consent expired
With Sealmetrics: Full 25-month view shows accelerating holiday growth

B2B SaaS Customer Lifecycle

B2B companies with 12-18 month sales cycles need to track:

• First touch → Lead → MQL → SQL → Customer (often 12+ months)
• Free trial → Paid conversion tracking over extended periods
• Feature adoption patterns across customer lifetime

Sealmetrics retains the entire journey without consent expiration destroying attribution data.

Content Marketing ROI

Blog posts and content assets generate traffic for years. Long-term analytics show:

• Which 2-year-old articles still drive conversions
• SEO traffic growth patterns over 24 months
• Content decay rates and refresh opportunities

This insight is impossible with consent-based analytics that delete data after 6-13 months.

Product-Led Growth Tracking

SaaS products need to understand:

• User activation patterns over first 12-18 months
• Feature adoption timelines (what features users adopt after 6, 12, 18 months)
• Cohort retention beyond consent expiration periods

With 25-month retention, Sealmetrics captures the complete product-led growth story.

GDPR Compliance: Why 25 Months is Legal

Data Minimization Principle

GDPR Article 5(1)(c) requires data minimization:

"Personal data shall be adequate, relevant and limited to what is necessary."

Sealmetrics achieves this by:

1. Not collecting personal data: No IPs, no cookies, no persistent identifiers
2. Aggregate data only: Session-based metrics, not individual profiles
3. Automatic purge: 25-month deletion ensures data isn't kept indefinitely

Storage Limitation Principle

GDPR Article 5(1)(e) requires storage limitation:

"Personal data shall be kept in a form which permits identification of data subjects for no longer than is necessary."

Sealmetrics complies because:

1. Data cannot identify individuals: Session-IDs are temporary and non-linkable
2. 25 months is proportionate: Reasonable for business analytics needs
3. Automatic deletion: Built-in expiration prevents indefinite storage

Legitimate Interest Assessment

Under Article 6(1)(f), three tests must pass:

Purpose Test: Is the processing necessary for legitimate interests?
Yes - Website analytics is a recognized legitimate business interest

Necessity Test: Is the processing necessary for that purpose?
Yes - Analytics requires data retention for pattern identification

Balancing Test: Do user interests override business interests?
No - Zero personal data means minimal user impact, business needs prevail

CNIL's 2020 guidance explicitly confirms cookieless analytics can operate under legitimate interest when no personal data is collected.

Best Practices for Long-Term Analytics

1. Leverage Full Historical Data

Don't limit queries to recent months out of habit:

// Bad: Only checking last 3 months
const recentData = await getAnalytics({ months: 3 });

// Good: Using full 25-month history
const fullHistory = await getAnalytics({ months: 25 });
const yearOverYear = compareYears(fullHistory);

2. Build Year-Over-Year Dashboards

Create dashboards that automatically compare:

• This month vs. same month last year
• This quarter vs. same quarter last year
• Rolling 12-month trends

3. Track Cohort Behavior Long-Term

Follow user cohorts through their entire lifecycle:

• Users from Q1 2023: What happened after 12, 18, 24 months?
• Traffic sources from 2023: Which generated best 2-year ROI?

4. Identify Long-Tail Content Value

Find content that generates value long after publication:

• Articles from 2022 still driving traffic in 2024
• Evergreen content that compounds over years
• Historical posts that become more valuable over time

5. Plan for Data Purge at 25 Months

When data reaches 25 months:

• Export critical insights before deletion
• Document key trends and patterns
• Update forecasting models with latest complete cycles

Frequently Asked Questions

Is 25-month retention GDPR compliant?

Yes. Sealmetrics operates under legitimate interest (Article 6(1)(f)) and doesn't collect personal data (no IPs, no cookies). The 25-month period is proportionate for business analytics needs and includes automatic deletion, satisfying GDPR's storage limitation principle.

Why not unlimited retention like some competitors?

While technically possible (since we don't collect personal data), 25 months provides the optimal balance between analytical value and demonstrating GDPR compliance through reasonable storage limits. It covers two full years plus seasonal buffer, which satisfies 99% of business analytics needs.

What happens to data after 25 months?

Data older than 25 months is automatically and permanently deleted from Sealmetrics systems. This cannot be reversed. Export any critical historical analysis before the 25-month mark if you need records beyond this period.

Do I need consent banners with 25-month retention?

No. Sealmetrics operates under legitimate interest, not consent. You don't need cookie banners, consent management platforms, or consent tracking. Your privacy policy should mention Sealmetrics usage, but no active user consent is required.

Can I reduce retention to less than 25 months?

Yes, you can configure shorter retention periods if your organization's data policy requires it. However, since Sealmetrics doesn't collect personal data, there's typically no compliance reason to reduce retention below 25 months.

How does this compare to Google Analytics data retention?

Google Analytics requires consent (cookie-based) and typically allows 14-26 month retention. However, when users withdraw consent or consent expires, Google Analytics must delete all associated data. Sealmetrics' 25-month retention is guaranteed regardless of user actions because no consent is required.

Can I track individual users across 25 months?

No. Sealmetrics uses session-based tracking, not persistent user tracking. Each visit generates a new Session-ID. This means you can see aggregate patterns over 25 months (traffic trends, popular pages, etc.) but cannot track individual users across sessions or time periods.

What if my business needs longer than 25 months?

For specific use cases requiring longer retention, contact Sealmetrics support. Extended retention may be possible for specific aggregated metrics that demonstrate business necessity and continued GDPR compliance. However, 25 months covers seasonal analysis, year-over-year comparisons, and most B2B sales cycles.

Does Plausible or Matomo offer better retention?

Plausible and Matomo offer longer retention options (unlimited in some configurations), but they store hashed IP addresses, creating higher personal data risk. Sealmetrics' zero-IP approach with 25-month retention provides the best balance of long-term analytics capability and privacy protection.

How do I access my 25-month historical data?

All Sealmetrics dashboard views and API endpoints automatically include the full 25-month history. No special configuration needed. Simply set your date range in queries to span up to 25 months, and Sealmetrics will return the complete dataset.

Is data deleted exactly at 25 months or gradually?

Data is purged on a rolling basis. When analytics data reaches exactly 25 months old (measured from the date of collection), it's automatically deleted. This means your oldest data is always approaching the 25-month mark, and you always have approximately 25 months of history available.

Can competitors see my historical data?

No. Sealmetrics data is completely private to your account. Unlike some analytics platforms that aggregate data across customers, your 25-month historical data is isolated and accessible only to users with your account credentials.

Conclusion: The Strategic Advantage of Long-Term Analytics

In a privacy-first world where consent-based analytics platforms lose historical data to consent expiration, Sealmetrics' 25-month retention provides a strategic competitive advantage.

Businesses using Sealmetrics can:

• Make better decisions with complete historical context
• Identify long-term trends that short-retention analytics miss
• Calculate true ROI for marketing channels with long sales cycles
• Optimize seasonally using multi-year comparison data
• Track customer lifecycles beyond consent expiration limits

All while maintaining zero personal data collection and full GDPR compliance.

Unlike Google Analytics (which deletes data when consent expires), Plausible (which stores hashed IPs), or Matomo (which requires complex configuration), Sealmetrics provides the simplest path to long-term, privacy-first analytics.

Ready to gain 25 months of insight without consent banners?

Start your free trial at sealmetrics.com and experience analytics that doesn't expire with user consent.

Additional Resources

• Complete Guide to Cookieless Analytics