I would like to be able to advise certain clients that a business visitor visa (B-1) is enough. With a B-1 visa, a foreigner can engage in any commercial transaction -- start a business in the U.S., sign contracts, invest in companies -- so long as it is not gainful employment. Moreover, because visitor visas are granted for both pleasure and business at the same time (B-1/B-2), foreigners in the U.S. usually already have these visas in their passports. No additional applications are needed.
Word to the wise: investigate another visa for business purposes.