We’ve touched on benefits here and there, but want to pull them all together to crystallize the case for responsive design.
There is one overriding benefit, and Mashable puts it well: “You build a website once, and it works seamlessly across thousands of different screens.” That sums it up, but specifics never hurt. Here they are:
Cost. Development of one site is cheaper. It requires a bit more coding during development, but certainly at a much-reduced cost when compared to building multiple sites for different devices. A single site also means only updating content in one place, too—which is another cost saver.
Future proofing. Responsive design sites have coding that enables proper viewing and access from many devices. When the next big thing comes along—and it will—the existing coding should be able to adapt. (Worst-case scenario would be a relatively easy coding modification.)
Retroactive. This is a developing issue, but web designers are determining how to incorporate responsive design in many existing sites.
Easier for search engines. Two sites with similar and sometimes identical content can cause problems for Google and other search engines. If the search engines have trouble, then your prospects have trouble finding you.
Faster for mobile users. A responsive design site should download quicker for mobile users, preventing frustrated visitors from trying another site.
Interface/putting best content/branding forward. Responsive sites keep your look and feel consistent and presentable. They also put key content forward. That is not always the case on mobile sites. And it’s definitely not the case when a site built for a desktop is accessed from a device that is a poor match.
SEOs. Google has said they prefer responsive web design, and Google still brings about 6-7 out of 10 visitors to sites. Other search engines also are likely to see benefits as well.