Q.Why should I use a responsive template?
In the Shop Manager at Design → Design templates, you can select to use a Responsive tempate.
There are responsive templates corresponding to all PC site HTML templates. If using a PC site template or an XHTML template, you should consider switching over to a responsive template.
Using a responsive templates confers many benefits. One such benefit is that it involves less effort in the future. There are many places throughout your website where you can set PC and mobile site text or options separately. With a responsive template, these are all combined, so you don't have to take the time to set up both sites.
Another benefit is user experience. Responsive templates display seamlessly on basically any mobile device, and the contents and design elements always match the PC site. This helps you project a coherent brand image while making your site easy to use.
Finally, responsive templates have a distinct advantage when it comes to search engine optimization (SEO). If you have two separate sites, then these sites are ranked separately by search engines. This means you need to run two separate SEO campaigns for each website. If you use a responsive template, then you can focus all your resources into a single SEO campaign for your one, unified website, and are likely to get better results.