30x-seo-content-decay（30X SEO 内容 decay）

Content Decay Detection

Find declining old content that needs refresh

What is Content Decay

Content "rots" over time:

• Information becomes outdated (2023 data is stale in 2026)
• Competitors publish better content
• Search intent changes
• Google algorithm updates

Result: Rankings drop → Traffic drops → Revenue drops

Detection Criteria

Trigger Refresh: Meeting any 2 criteria = needs refresh

Workflow

Method A: With GSC Data

User provides GSC export (CSV)
↓
Analyze each URL:
- Impression trends
- Click trends
- Average position trends
- CTR trends
↓
Identify decaying content
↓
Output refresh priority list

Method B: Without GSC Data

User provides URL list
↓
Check each page:
- Publication date / Last updated date
- Content timeliness signals (years, "latest", etc.)
- Competitor SERP analysis (your content vs Top 10)
↓
Identify potentially decaying content
↓
Output recommendation list

Output Format

# Content Decay Report

## High Priority Refresh (High Traffic Impact)

| Page | Published | Traffic Change | Rank Change | Issue | Recommendation |
|------|-----------|----------------|-------------|-------|----------------|
| /blog/best-crm-2024 | 2024-03 | -45% | -8 positions | Year outdated | Update to 2026 version |
| /guide/remote-work | 2023-11 | -30% | -5 positions | Tool recommendations outdated | Update tool list |

## Medium Priority Refresh

| Page | Published | Issue | Recommendation |
|------|-----------|-------|----------------|
| ... | ... | ... | ... |

## Refresh Recommendations

### /blog/best-crm-2024

**Problem Diagnosis**:
- Title contains "2024", outdated
- Pricing info may be inaccurate
- Missing 2025-2026 new features

**Refresh Checklist**:
- [ ] Update title to "Best CRM 2026"
- [ ] Verify all prices
- [ ] Add new tools (X, Y, Z)
- [ ] Update screenshots
- [ ] Check all external links are valid
- [ ] Update dateModified in Schema

**Estimated Impact**: Recover ~40% traffic

Refresh Strategies

Light Refresh (Quick Update)

When: Minor information outdated

• Update years
• Update prices/data
• Fix dead links
• Update dateModified

Medium Refresh (Content Update)

When: Content partially outdated

• Rewrite outdated sections
• Add new information
• Update images/screenshots
• Add new H2 sections

Heavy Refresh (Content Rewrite)

When: Content significantly outdated or intent changed

• Re-analyze SERP intent
• Rewrite most content
• May need new content-brief
• Keep URL (preserve 301 historical equity)

Usage

# With GSC data
/seo content-decay --gsc [csv-file]

# Without GSC, provide URL list
/seo content-decay --urls [url-list]

# Analyze entire site (crawl sitemap)
/seo content-decay https://example.com

Related Skills

Best Practices

1. Regular checks: Run decay detection quarterly
2. Prioritize high-value pages: Refresh high traffic/conversion pages first
3. Keep URLs: Refresh rather than recreate, preserve historical equity
4. Update dateModified: Tell Google content has been updated
5. Internal link check: Check if internal links need updating after refresh

[PROTOCOL]: Update this header on changes, then check CLAUDE.md