Now that we’ve answered the question “what is a subdomain,” let’s look at a few examples of when to use a subdomain: 1. eCommerce Due to the complexity of online stores, businesses often choose to create a separate site architecture to handle transactions. This distinction allows companies to offer different functionalities than the main site needs or has available. The store.playstation.com subdomain, for example, is a platform where users can purchase games for their consoles. 2. Mobile Online platforms that require an overhaul to perform well on mobile devices usually host their mobile sites under dedicated subdomains. For example, Facebook crafted a distinct interface for its mobile users under m.facebook.com. The company shaped the layout to fit a mobile device’s oblong shape. 3. Location Companies providing localized or geo-specific content can easily do so using subdomains. For example, Yahoo curates UK-related news using uk.yahoo.com and US-related news on us.yahoo.com. 4. Audience Subdomains allow businesses to create unique sites targeting distinct audiences and even password-protect them if needed. While most Lyft users dwell in the ride.lyft.com subdomain, those interested in the company’s self-driving initiative can visit the autonomous.lyft.com subdomain. 5. Blog Because blogs often target topics and keywords not directly related to the rest of the site, you might consider situating your blog on a subdomain. The Library of Congress massive site caters to a different audience than its blogs. So, blogs.loc.gov hosts hundreds of articles on a different interface where readers can browse and search for their desired content. 6. Support When Frequently Asked Question pages don’t thoroughly answer all customer questions, site owners can create a dedicated support platform under a subdomain. This organization can make the platform easy to navigate and better optimized for search engines. A quick glance at support.yotpo.com shows that the platform’s subdomain has a unique, carefully-designed and complex structure that addresses users in need of assistance. 7. Content Sites that craft extensive, highly-branded content for certain subjects often choose to work with dedicated subdomains. Products, films, teams and publications with divergent content might use subdomains to distinguish their brands from the umbrella organizations. As one would expect, the content found on The New York Times functions drastically differently from the content found on NYT Cooking (cooking.nytimes.com). Separating the content allows each brand to signal its own authority to search engines. 8. Language Creating independent subdomains for each language enables organizations to keep their web addresses clear and cohesive. This is a common practice in international SEO. For example, Wikipedia has a separate subdomain for each language. Interestingly, the es.wikipedia.org homepage differs not only in language from the en.wikipedia.org homepage but also in content. 9. Forum Due to the intricacy of online community building, forum creators commonly use dedicated subdomains. Take wordreference.com: the root domain stands as a bilingual dictionary. However, forum.wordreference.com is a place for users to ask questions and discuss the meaning and proper use of terms and phrases that have yet to make it into the root dictionary. 10. Function Amazon created a subdomain for their AmazonSmile initiative. Whenever a user shops on smile.amazon.com, Amazon donates 0.5% of eligible purchases to the charity of the user’s choice.