What are businesses missing by NOT embracing mobile customers?

I moved from the traditional ad buying marketplace of NYC to Denver to begin working on digital start-ups and quickly found that mobile-sites and applications could IMMEDIATELY open businesses and services to a new consumer base and marketplace.

It's frustrating to see so many traditional businesses (and even new businesses) turning a blind eye to the now 50% of America on smartphones - using smartphones to not only search local and national businesses but conduct transactions via mobile. Consumers are smarter and more so are their tools.

After 3 years bouncing around the digital marketplace and learning the landscape better, I have landed myself in the role of Marketing Coordinator for a Denver based mobile and web development company. Here* is the first hand look at not only the mobile technologies and fantastic turn-key tools they offer to businesses, but an inspiring look at entrepreneurs putting their ideas in motion.

No, not every new or existing business needs or will need a "mobile application", but with half of America using a phone to find you, what can they accomplish on your site? The greatest gift I can offer the mobile-moving business is a consultative and appropriate direction. Mobile site-versions WILL many times be the difference between 1 pageview and 10 pageveiws with an action attached. An appointment set, a phone call made or even a purchase! Not a full blown mobile application, "mobile site versions" (sometimes combines with SEO and web-redesign) are an improvement allowing users to effortlessly find what they need to on your businesses site via their smartphone.

I guess the questions is: Has mobile not given enough data on ROI for every business to be making the investment?

Maybe a better question: Mobile App vs. Mobile Site? Which do I build first?

Attached is a great answer with cool infographic to break down the highlights.
http://mashable.com/2012/06/06/mobile-site-mobile-app-infographic/