The immediate benefits of a single-page website is the content is presented in simple, easy and workable fashion for the user.
Single page sites immerse the user in a simple linear experience. There’s a clear beginning, middle, and end. In fact, the scrolling nature of single-page sites makes them well suited for mobile users who are accustomed to the gesture.
Some experts argue that single page websites even have higher conversion rates as compared to larger, multi-page websites. 37signals did a study of single-page conversions and found that a single long landing page leads to 37.5 percent more signups, compared to a multiple page version.
One-page navigation, of course, is more straightforward than a larger site for sites which serve a single purpose. That purpose might be selling one product or offering one service, for instance. If your goal is to tell a story, then single-page sites are also a natural choice for visual narratives.
The biggest danger is falling into the trap of stuffing “10 pounds of stuff into a 5 pound bag.” Single page websites just can’t hold life, the universe and everything. As described in the free e-book Web UI Best Practices, they require careful visual hierarchy and plenty of discipline.
As your categories of content increases (e.g. blogs, news, services, products), the more a single page site becomes less feasible. From a more technical standpoint, single-page sites are also less search optimized than multi-page sites. With tons of content and images on one page, they can also load slower.
Search engine algorithms, of course, seek relevancy – they match queries with content. While a single page site may improve relevancy for your primary keywords, it’s more likely it will dilute relevancy for sub-topics and terms that might rank better, or at all, on their own pages.
Defining content sections and using anchor links is the suggested method for increasing single-page SEO. Using H1 tags is also highly advised. As an H1 signals that what follows is distinct and separate from the rest of the page, it’s a good way assure SEO of a single-page site. (Use only one h2 per section of your single-page site).