Mobile commerce is an inevitable reality considering the smartphone penetration in the market today. Web access through mobile traffic will exceed the desktop traffic in less than a year from now. When that is how fast the mobile market is growing, mobile commerce is definitely a channel to tap into for retailers. What better way to get headway into that channel than considering responsive design for your e-commerce site. What more, the responsive design gives a headway to tap the tablet market also without any extra effort.To answer the question of whether a responsive design based e-commerce site is the need of the hour, it is a yes and a no. Not having one is not a show stopper yet. But having one can significantly boost sales. Here are four good reasons why you should consider Responsive design right away.Amazon: A Billion $ in sales through m-commerce.Amazon is a good representative of anything e-commerce. They reported a Billion dollar sales in m-commerce alone last year which is definitely a strong indicator of the rising trend of mobile commerce. The mobile trend was once limited to casual browsing. Now we see that translating to serious business transactions. With PayPal and other payment gateways optimizing their services for mobile, this is the right time to have a jump-start in that direction.Mobile research of products while watching TVOne of the most known ways among consumers to research products while watching TV is by browsing on the phone or a tablet. If you have a m-commerce powered site, this can translate to immediate business. Else, there is a huge a lag between the time the consumer views the ad and remembers to view your site to actually review the product. This lag can actually result in a lost sale. With a responsive design, you will be offering a seamless experience for your customers to browse your product catalogs and make a buy as well.40% of people access Facebook from their phones Facebook is one of the biggest ad channels for e-commerce. Every retailer is spending huge bucks on Facebook ads to reach prospective customers. When so much resource is pumped into that channel and 40% of the traffic accesses the channel through mobile, it is only wise to make an investment into making the site optimal for mobile and other devices.Mobile commerce predicted to grow at 39% every yearMobile commerce is predicted to grow at at-least 39% year on year till 2016. What this means for retailers is that, just by having a mobile site, they boost their sales. One may even argue that by lacking a mobile site, retailers may lose business. 39% is a significant number that can’t be ignored. There are more smartphones sold in a day in the US than there are babies born which quite explains the huge growth numbers.Building Responsive designs Though much bigger companies are looking at building native apps for their commerce sites, now, it is definitely more practical to build a site with responsive design. This strategy takes care of various devices and screen sizes without the need to invest much about developer resources. Responsive designs not only cover mobiles, but also tablets and other devices that are widely used. The Information architecture and content structure has to be redone to make your design responsive. If you use any of the e-commerce platforms like Magento, you have the option of buying responsive themes off the shelf that works like a magic across devices.