You also need to account for exchange rate and processing fees. Some recipients may not receive 1 dollar. Edit0: Also, I just realised, many poor people do not

You also need to account for exchange rate and processing fees. Some recipients may not receive 1 dollar. Edit0: Also, I just realised, many poor people do not have means to exchange dollar into their local currency. So sending them 1 dollar through post is going to be a waste. Edit1: Most countries will not allow this due to hawala which creates black money.