Everybody is talking about responsive web design, where a website is developed in such a way it adjusts to fit on desktop, tablet, and smartphone browsers.
Should your business consider responsive or mobile web or mobile app to be mobile friendly, the answer could be one or combination or even mix of all three depending upon the requirement.
Mobile Internet usage has been skyrocketing over the last few years but businesses may ignore being responsive only if your business does not depend on website to stay in business or have no competitors or you have an alternative way to reach this mobile audience.