Business As Mission (BAM) is a term that carries a wide variety of different connotations. At its foundation, it implies that simply doing business can glorify God. Hopefully it recognizes that a Christian can serve God as fully and completely in business, as one can in full-time ministry. Ultimately, it recognizes that business can be a powerful tool for the Kingdom of God.
However, it generally refers to activities undertaken in a cross-cultural context, with the goal of establishing viable businesses that can have a positive impact for Christ, in a sustainable manner. Another term that has been used to describe Business As Mission is "Christian Social Entrepreneurship." Social Entrepreneurship requires that one track more than a single bottom line, such that some "social" purpose has equal standing with profitability. In Business As Mission, profitability and traditional business metrics still have valid standing as drivers of sustainable business endeavors, yet there also exists a social bottom line, and an awareness of the "Kingdom Impact" of the business.
Transformational Ventures (www.transformationalventures.com) is a newer endeavor of World Venture, the missionary organization we are working under, which has a Business As Mission focus. If you are interested in learning more about both the theory, and actual examples of how Business As Mission is being carried out, you may want to spend some time reviewing this site.
Another aspect of Business As Mission, is recognizing that God can, and wants to, use the skills that Christians have gained in the "secular" world, for His glory. You may not realize just how many opportunities exist for business professional to exert a positive, Christian influence on the world, but your skills are needed. If you are interested in seeing what opportunities exist, check out BAMmatch, at bammatch.com.