Direct answer
Migrations succeed through controlled scope, stable mapping, rehearsed validation and post-launch observation—not an invented percentage of transferred equity.
Practical steps
- Freeze baselines and owners.
- Map content and redirects.
- Rehearse in a noindex environment.
- Launch with rollback signals.
- Monitor crawl, index coverage, queries and outcomes.
Common mistakes
- Changing everything at once.
- Chains and homepage redirects.
- Removing the old property too early.
Limitations
- External systems take time to update.
- Causal isolation is difficult during broad change.
Primary sources
- Understand the JavaScript SEO basics — Google Search Central; 2026-03-04; 2026-08-14.
- A Quantitative Study of Forum Spamming Using Context-based Analysis — NDSS Symposium; 2007-02-28; 2026-08-14.