.com = 52% of all domains. .co = 78% mistaken for .com. .io = tech credibility. Extension choice impacts trust, memorability, email deliverability.
The .com Premium
US consumers type .com automatically. 67% assume .com if extension not specified. Your .co site? They land on competitor's .com.
Trust Gap
.com = established. .biz/.info = spam associations. Banks, law firms, healthcare = 94% use .com. Industry credibility demands it.
Email Deliverability
Gmail/Outlook spam filters flag obscure TLDs harder. .xyz/.top = 43% higher spam folder rate vs .com. Your cold emails already fighting uphill.
The .io Exception
Tech startups embrace .io. Developers recognize it. Dropbox.com, GitHub.com dominate, but Stripe started Stripe.io. Works IF audience = tech-savvy.
Geographic Confusion
.io = British Indian Ocean Territory. .co = Colombia. .ai = Anguilla. Most users don't know. Risk: Geopolitical changes revoke TLD (happened .su Soviet Union).
Trademark Coordination
Registering MyBrand.io? Still need MyBrand.com defensive registration. Competitors squat .com variants. USPTO doesn't distinguish TLDs in likelihood-of-confusion analysis.
The Compromise
Perfect name available on .io only? Launch .io, buy .com later when affordable. Redirect .com to .io immediately. Prevents squatting, captures typers.
Trademark Lens checks domain availability across 15 TLDs simultaneously - see which extensions clear before committing to non-.com strategy.