Everybody is proclaiming there’s no room for non-responsive websites anymore. Even now, when the mobile web is a huge part of how everyone connects to the Internet, it’s good to think about if the tools we’re using are the right ones for the context. That is why understanding and involving metrics and demographics in the design process are so great.
For example, we believe it is really important to have a fully responsive design for our checkout pages. Even small changes in checkout page conversion can make a big difference to our customers. Whilst only ~3% of visitors to our checkout pages are on a mobile, having an appropriate design can significantly impact their conversion. So it’s worth investing in, even for a small proportion of our visitor base.
Although if you are expecting some kind of interaction (like the aforementioned responsive checkout) not only mobile-friendly designs but the overall simplicity of the process is a must.