It’s been a long time since we covered one of the most fundamental building blocks of SEO—the structure of domain names and URLs—and I think it’s high time to revisit. But, an important caveat before we begin: the optimal structures and practices I’ll be describing in the tips below are NOT absolutely critical on any/every page you create. This list should serve as an “it would be great if we could,” not an “if we don’t do things this way, the search engines will never rank us well.” Google and Bing have come a long way and can handle a lot of technical challenges, but as always in SEO, the easier we make things for them (and for users), the better the results tend to be.
#1: Whenever possible, use a single domain & subdomain
It’s hard to argue this given the preponderance of evidence and examples of folks moving their content from a subdomain to subfolder and seeing improved results (or, worse, moving content to a subdomain and losing traffic). Whatever heuristics the engines use to judge whether content should inherit the ranking ability of its parent domain seem to have trouble consistently passing to subdomains.
That’s not to say it can’t work, and if a subdomain is the only way you can set up a blog or produce the content you need, then it’s better than nothing. But your blog is far more likely to perform well in the rankings and to help the rest of your site’s content perform well if it’s all together on one sub and root domain.
