Based off the information at the site and the tweets, the most sensible explanation is that it's a single order that gets attempted, but the cart gets cleared. Rather, it's the sheer number of locations that McDonalds has licensed it's name to that cause the dollar value.

Given the cost of $1 for a cone, he's checking 18,752 locations per minute, or about 1.28x the number of branded restaurants in the US + Canada.