The difference between indigenous community and people living in suburbs is that these communities are 100s of km from anywhere.  people there gettheir money and the only place to spend it is the ONE shop.  Giving them card instead of cash means that the only change is on what they can buy, not where they buy.  It limits the amount of grog and cigarettes, and the kids get fed better.   That is why it has  no impact on the families who were already spending their money on food. 

In large cities, the choice of where to shop is huge, and price difference is large.  Giving card to poor people who are no drug addicts, alcoholics or smoke too much, will mean that their survival strategies will be curtailed and their income in fact reduced.

This morning I went to our market and bought some apples for $1.20/kg, grapes $1.45/kg , bananas $1.50/kg nectarines $1.79kg. on the way home I stopped in our local supermarket and walked through the fruit/veg section to get some milk.  Bananas were $3,40, nectarines $3.80/kg, apples $5/kg, grapes $3.79kg .  So if i bought 1kg of all these at the market I would have paid $5.94, for identical shopping at the supermarket it would have been $15.99, that is $10 difference just on 4 items, and there are places that are even cheaper than our market.  So can you understand what impact the card will have on ordinary poor people who do not waste their money, and who  are managing just fine due to wise shopping?  It will mean their kids will have less food, just because there is a small % of people who spend their money on drugs.  Do you really think that is a step in right dirrection?