Firstly what is a Responsive WordPress Theme? Wikipedia states :
“Responsive web design (often abbreviated to RWD) is a web design approach aimed at crafting sites to provide an optimal viewing experience—easy reading and navigation with a minimum of resizing, panning, and scrolling—across a wide range of devices (from desktop computer monitors to mobile phones).”
Basically that is true, although it uses a bit too much techno-jargon for my liking. Generally we refer to a responsive theme design as a design that takes into account all or as many of the possible devices that will be used by web surfers to view a web site. Some examples of the types of devices are iPads, PC’s (both Apple and Windows based), Android tablets, Smart phones and there are a few more that I have forgotten so I won’t bother mentioning
All these different devices have different hardware and software specifications but the crucial specification that generally dictates a users experience on the web is the screen size. Screen size is therefore generally what dictates how a responsive theme will behave. So what generally happens is that the theme detects what kind of device is actually accessing the site and serves up different html, php and and usually the most importantly different css/style sheets.
Most themes will either adjust the css depending on the width of the browser (usually in pixels) or the type of device. Some themes will do a bit of both. It is not all that hard to do and the beauty of this kind of design is that the images will generally get resized on the fly also. No need to adjust image sizes in php or rebuild smaller versions of each image.
Are Responsive Themes Important?
Um… Hell yeah! Why? Because Google says so! The Guru’s at Google have finally decided to pick a clear winner in the responsive theme vs redirect to subdomain method. What is the redirect method? Well basically when you detect a mobile or non-pc device you redirect the user to a subdomain that has been specifically set up for mobile devices. Google previous to June last year were not clear on what method they preferred. However now with that above linked to statement, Google has made it clear that responsive theme design has won that particular war. I have always advocated a responsive solution to different sized device screens. However, having said this there are still some big sites not using responsive methods and they seem to be doing just fine in the traffic stakes, Techcrunch.com to name just one important site!
So for now non-resposive handling of mobile devices is probably fine and your SEO should not take a hit. However, knowing how quickly some of these big sites react to Google Search Engine Optimization statements. We should see them moving to responsive designs relatively quickly and if the big guys move then Google will fast-track the negative affects of non-responsive themes.
So go ahead move to that responsive theme as soon as possible, you won’t regret it.