With mobile technology operating on a continual cycle of development and mobile usage still regularly increasing there really isn't even a question anymore; it is time to switch to a responsive web design.
What is the difference between a Responsive Design and other options? A responsive website has the ability to detect the type of device the user is connecting with, such as a tablet or smart phone. Then, the website responds to the device by using the device type to then adjust the various design elements so that they fit the parameters of that device's screen.
This type of design allows for a seamless transition for users regardless of device.
There is also what is called a mobile friendly website which as the name entails, is designed to look good on mobile devices. The information will be the same across all devices but navigation has to be designed in a simple format that works well regardless of device.
This type of design is different from responsive in that while it does provide a consistent website experience, the website itself needs to be simple and functional and cannot handle any complex functionality which is very limiting.
There is also Adaptive Web Design. Much like a mobile friendly design, this works best for a simplified site rather than complex. Overall a responsive design is the most versatile option.
Why do you need Responsive Design?
A responsive web design (RWD), or even one of the other mobile design options, has become more critical for a number of reasons:
Web Traffic - First and foremost a responsive website will earn you more traffic than a non-mobile friendly site. Back in 2015, Google announced they would begin to factor in mobile friendliness as a ranking signal.
Load Speed - A responsive design is based on the concept of working well on all devices and as such typically places importance on load speed, which is critical when it comes to reducing site abandonment.
User Experience - The user experience is always an important piece of the conversion puzzle. The better the experience, the more likely a user is to convert - it is just that simple. What a responsive web design adds to the experience is seamlessness across platforms.
SEO Efforts - If you want to rank high in SERPs then having a responsive design will only help. Load speed and the user experience are also evaluated and considered within Google's complex ranking algorithm.
Online Sales - If you sell products on your site then having a highly functional mobile site is paramount to success. Statistics show that 80% of consumers regularly use smartphones to shop online and some even shop online while in stores to ensure they are getting the best deal.
Cost Effective - For those that currently maintain a mobile and desktop site, combining to one site will save time and money in the long run. Only one site will need to be updated, optimized, and focused on for marketing. This will end up increasing your ROI in the long run.
