The key principles of domain selection and structure for optimizing Google search performance can be summarized as follows:

1. Short and Memorable

• Keyword Priority: Include target keywords in the domain (e.g., bestrunninggear.com), but avoid over-optimization (e.g., cheap-best-running-shoes.com).

• Branding First: Prefer unique brand names (e.g., nike.com) over generic terms.

2. Top-Level Domain (TLD) Selection

• Preferred: .com – Globally recognized and trusted by default.

• Country Code TLDs (ccTLDs): Such as .cn (China) or .de (Germany), which boost local search performance.

• New gTLDs: Like .shop or .tech – Ensure relevance to the brand.

3. Subdomains vs. Subdirectories

• Subdirectory (Recommended): example.com/blog
  – Treated as part of the same site by Google, consolidating ranking power.

• Subdomain: blog.example.com
  – May be treated as a separate site, requiring independent optimization (best for distinct content sections).

4. HTTPS Security

• Mandatory: HTTPS is a Google ranking signal, and browsers flag non-HTTPS sites as “Not Secure.”

5. Avoid Problematic Structures

• Hyphens: Use no more than one (e.g., my-brand.com); excessive hyphens (e.g., buy-cheap-shoes-now.com) appear spammy.

• Length Control: Keep under 15 characters (excluding TLD) for memorability and shareability.

6. History & Penalties

• Check for Penalties: Avoid domains previously penalized by Google (use Google Transparency Report).

• 301 Redirects: When changing domains, implement full redirects to preserve SEO value.

7. Mobile Adaptation

• Responsive Design: Ensure the domain’s pages are mobile-friendly (critical for mobile rankings).

One-Sentence Summary

“Brand-relevant, concise, secure, and well-structured” is the core principle of a Google-friendly domain.

For deeper insights (e.g., subdomain strategy or HTTPS setup), feel free to explore specific aspects.