The 260 million dollar figure isn't for store visitors, it's for stores + websites. From walmart.com:

> Today, nearly 260 million customers visit our more than 11,500 stores under 63 banners in 28 countries and e-commerce sites in 11 countries each week.

> According to statisticbrain[2], Wal-Mart stores (location not specified) have 100 million customers (not visits) per week.

The source you cited looks like the location they're referring to is worldwide. They cite "Total Wal-mart sales annually" and that lines up with their total global revenue, so I think it's a fair assumption that their "Total numbers of customer per week" would likewise be globally.

Walmart stores are also convenient to a lot of people. I'm not their target demographic and don't really like grocery shopping there in general. However, one is nearby and it's pretty common that I'll pop in to pick up something even though I don't generally do a "weekly grocery shopping" there.

> Everyone does groceries probably once a week.

This isn't true by a longshot. The 300m figure is every man, woman, teenager, child, and infant in America, and you only need one person per family going for a weekly grocery trip. And that's of course ignoring the people who don't do weekly groceries. On top of THAT, the 30% number doesn't seem particularly reasonable either (though that one is at least the only remotely plausible thing you've said).

It says visitors, not visitations.

I think the word you're looking for is "basic arithmetic literacy". This should be obvious by the fact that it turns out the 100 million figure is for worldwide visits to stores, and only something like 40% of Walmart stores are even in the US. For those of us who aren't hobbled by a desperate need to be offended, little arithmetic spot-checks like the GP comment's are actually useful (in this case, revealing that his assumption of US-only visitors was flawed).