I routinely examine user statistics for the sites I manage, because I’m interested in knowing where visitors are coming from, what parts of the sites they spend the most time viewing, and more recently, what kinds of devices they are using to view the sites.
I have been surprised at how quickly the transition from people viewing only on laptops and desktops to viewing on mobile devices has occurred, even on graphic-rich eCommerce sites. According to Search Engine Watch, Mobile Internet usage exceeded PC/Mac usage in 2014. Comscore research shows that, as of March 2015, “…the number of mobile-only adult internet users exceeded the number of desktop-only internet users.”
People are using their smartphones to shop and to learn more about products, even when they are shopping in a store where they could ask a human for information about those products!
It follows that, if you hope to reach mobile-using customers, your site should be responsive; that is, its layout and functionality needs to automatically adapt to whatever device is being used, whether desktop, laptop, tablet, or smartphone.
So, when a potential customer asks Siri or Google for information about a product or service you offer, you will want to have a site that is well-optimized for search, and is easy to view on their smartphone!