When should a subfolder strategy be chosen instead of a new domain?

Short answer: The default choice is the subfolder: the existing domain's authority, crawl history, and brand signal carry into the new market. A new domain (especially a ccTLD) is worth it only with a strong local trust expectation, legal requirements, or positioning independent of the main brand.

When the subfolder wins

• Authority cost: a new domain builds its link profile from zero; a subfolder benefits from existing signals on day one.
• One operation: content production, technical maintenance, and measurement stay on one infrastructure.
• Budget efficiency: every earned backlink accrues to one domain instead of being split.

When a new domain is justified

• ccTLD trust: in some markets users visibly trust the local extension more; .de in Germany is the familiar example.
• Legal, hosting, or licensing requirements.
• Products, joint ventures, or spin-offs positioned away from the main brand.

TYS Digital Performance grounds this decision in three data points: the extensions dominating the target SERPs, the brand's local investment capacity, and the existing domain's authority level; performance is then tracked against a baseline.