More than nine of 10 US consumers made a purchase at Walmart in 2016, according to new data from the NPD Group.
The new "Checkout Penetration Index" offers a different way of thinking about market penetration, asking simply what percentage of consumers bought at a particular store or restaurant. Walmart, Target, Walgreens, Dollar Tree and CVS made up the top 5 for retailers.

NPD said Dollar Tree, at 71%, was the biggest gainer among the retailers on the list, rising 3 percentage points over the previous year. Chick-fil-A topped the gainers among restaurants, increasing by 5 percentage points.
The list has some surprises, including Michaels Stores, which registered 38%. At that level, it's just 4 percentage points behind Amazon.com.
On the other hand, the list looks pretty similar to a ranking based on sheer square footage. Here are the top 10 retailers in the US, based simply on total square footage, according to the eMarketer Retail and Restaurant companies database: