Why Export? 

96% of the World's Population is OUTSIDE the US.  Why bet your business on the 4% of customers domesticially?
75% of the world's upcoming middle class and purchasing power is outside of the US.
Access to larger markets - by exporting, companies often tap into larger or more lucrative markets. 
Diversification of Revenue Streams - Exporting reduces dependency on a single market.  Economic downturns in one region might be offset by growth in another.
Economies of Scale - Serving more markets allows companies to increase production, often reducing per-unit costs and boosting profit margins. 
Competitive Advantage - Operating in international markets can drive innovation, improve product quality, and make firms more competitive both domestically, and globally.
Exposure to Growth Opportunities - Many emeging markets have higher growth rates than developed ones, offering businesses the chance to grow faster than they might in stagnant or saturated domestic markets. 
Extend Product Life Cycles - A US product at the end of its domestic life cycle may be totally new to an international market.
Growth - Companies grow 2-4 times faster than those that only sell domestically.  And, they are more resilient during economic downturns.
Companies who export report higher wages, which can lead to workforce retention.
Profitability - Exporting firms are 8.5% more productive and 17% more profitable as reported by the International Trade Centre.
97% of US exporters are small or medium-sized enterprises; and they account for 33% of total US export value.  Most manufacturers export reactively to no more than 2 countries (typically Canada/Mexico), missing growth opportunities in other countries.