By default, your Silk site runs on a subdomain of silkapp.com. This means your site can be found at a URL such as http://yoursite.silkapp.com. Yoursite being something you choose yourself during sign up.
It is possible however, to run Silk on one of your own domains. This way you could have a URL like:
In the first case, you register an entirely new domain name, which you dedicate to your Silk site. In the second case, you use an existing domain, and assign one subdomain to your Silk site.
If you want to learn more about pricing of custom domains, let us know.
Besides custom domains, we also support custom templates.