Google has recently announced that it will be rewarding websites which are “mobile friendly” with better rankings, making it all the more important. “Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high quality search results that are optimized for their devices.”
Read our important article which sets out for Magento e-commerce websites the pros & cons of responsive design compared to a separate mobile store.