The extension is the last part of the address — .com, .net, .plumbing. Technically they're interchangeable: browsers don't care, and any of them can host a perfectly good website. In practice, people have habits, and habits matter when your address is your business card.

.com

Still the default. People assume it. When someone hears "Dave's Plowing dot com" they type it without thinking, and when they see a .com on a truck they don't wonder what it is.

For a local service business, .com is the safest choice, and it's the cheapest to renew. If your exact name is taken, add your town: davesplowingbuffalo.com, davesplowinggi.com. Slightly longer, entirely fine.

.net and .org

.net was meant to be the network alternative to .com and has become the standard second choice. Nobody blinks at a .net for a small business. Renewal is similar to .com.

.org reads as a nonprofit to a lot of people. Using it for a for-profit snowplow business isn't illegal or harmful, but it sends a mixed signal, and a few directories assume it means an organization. Use it if you're actually a charity.

.us and country extensions

.us is fine and cheap, and it says "American business" without saying much else. For a purely local trade it's a reasonable pick, especially if the .com is gone.

Country extensions (.ca, .uk, .co.uk) only make sense if you actually operate there. A .ca for a Buffalo plow company would confuse people — and you'd need a Canadian presence to register one anyway.

The new extensions

Since 2014 there have been hundreds: .plumbing, .services, .roofing, .studio, .contractors. They look clever in the search box.

Three problems:

• Renewals are expensive. A .plumbing might be $12 the first year and $45–$70 to renew. Ten years of that is a lot for an address.
• People don't trust them yet. Some spam filters and directory forms treat newer extensions more harshly. A few email providers are more likely to junk mail from them.
• They're hard to say. "Dave's Plowing dot plumbing" needs explaining. "Dave's Plowing dot com" doesn't.

There are exceptions — a .studio for a photography studio, a .coffee for a café — where the name and extension reinforce each other and the business is not relying on the domain to be typed from memory. For a plumber, no.

What actually matters more than the extension

The name in front of it. A short, spellable, plain .com beats a clever name on an exotic extension every time.

Ask yourself: if a customer hears your address once, in a noisy kitchen, with a bad phone connection, can they type it correctly an hour later? If not, the problem isn't the extension.

A quick decision

1. Is yourbusiness.com available at a normal price? Buy it.
2. Is yourbusiness + your town available as .com? Buy that.
3. Is .net available? That's fine.
4. Everything else: shorten the name, or start on a free address and revisit later.

Don't spend two evenings on this. An address you own is a small, cheap thing that can be changed later — changing it is possible, just annoying.