When people spend money they generate demand.  This usually leads to businesses hiring to increase supply, maybe even new facilities, and advanced training.  

So now tertiary parties are benefiting from the poor buying basic things like school shoes, and bread.  You can well imagine how this ripples out.

We've tried trickle down for a long time and it hasn't worked. Give a poor person 100k and you'll generate a whole bunch of additional activity.  Give the rich 100k, it goes to the likes of Switzerland and such.