The question asked by customs agents at most borders is, "Here for business or pleasure?" to find out if one requires a VISA to enter the country. For example, online consultants who never visit the country physically do not require a VISA. And in fact, one can routinely visit American clients for sales, relationship building or presentations. The problem arises when the work is done physically (e.g. building a home, wood logging, chemical waste services, etc.) within the country that cannot be completed outside of it (or when living and working within the country without citizenship) - that requires a permit. Be aware that some countries still require a special tourist VISA even when only visiting for pleasure.