The country can sell the excess yield from domestic consumption to consumers in other countries. Cause the country and affect the standard of living of the people and do good, get to know new products that cannot be produced in the country, people use products that help facilitate those which do not have to import from foreign countries. development of the domestic manufacturers of new technology, including new products that affect the advancement of economic, social and political, both direct and indirect. Citizens use good quality items at a cheap price, that is, each country may not be able to produce all kinds of goods, due to the expertise of each country in each type of production is not the same. Some countries may produce one good and the other low-cost countries may produce other products and lower costs. The two countries will choose their products, expertise, and there is a sale or Exchange will be beneficial to both countries and more than. The disadvantage is that this may cause import goods from overseas. If this occurs, the unbalanced by imported than exported, continued to make the country the trade deficit and lead to a deficit payments affect to a stable currency and the country's economy, the most damage.