A question from Yahoo! Answers:
When did trade of goods and services begen?
Trade in services predates the existence of the human race; is it often observed in primates. In a family group of monkeys or apes, individuals are much more likely to groom those who have groomed them in the past.
very nice. that is just the thing i want. (.)-(.)
Well, I wanted to know WHAT YEAR trade began. This response from Yahoo! Answers was not very detailed enough. More work please, people!