A mobile-friendly site (or app) is not an end; it is a means to that end. To avoid failure, disappointment and embarrassment, companies must set clear business objectives, do the due diligence on who, what, when, where, why and how.
With mobile search surpassing desktop search in many countries, including the US, and Google now promoting websites in search results that perform better on a mobile device, a mobile-friendly site is now an imperative for all companies.