That’s probably about right figuring around 15% of the country is on food stamps. Poor are more likely to shop at Walmart than at more expensive retail stores.
When 1 out of 6 Americans are on food stamps or EBT, the Walmart % data in the ball park.
“Why are 47 million Americans on food stamps? It’s the recession ... http://www.washingtonpost.com/blogs/wonkblog/wp/2013/09/23/why-are-47-million-americans-on-food-stamps-its-the-recession-mostly/ - -
“There’s a fairly basic question at the core of the current food-stamp debate in Congress. Why has the program grown so rapidly over the past few years — to the point where 47 million Americans, one-sixth of the country, now receive food stamps?”