Misleading title: this is about how the author's app reached a high rank in the Mac App Store for a specific category yet he only saw 70 cents in profit as a result (one sale).
Having a headline of "One download was enough to get me to #18 on the app store" is not only clearer, it's also arguably more compelling.
FWIW I thought the article was about how the author reached a top rank by paying someone or investing in ads for 70 cents.
But the charts in question are "Top Paid" and "Top Grossing". So it does seem like a very odd result.