The average self-published book sells 150 copies. Theoretically that's the point at which an author has exhausted his friends and family, and starts to sell books to strangers who spend their hard-earned money based on reviews, advertising, and word-of-mouth.
When I published The Single Staircase, I saw that number cited a couple places. As far as I know, there's no way to prove its validity. But still, I fixed 151 in my head as the number at which I'd qualify the book as a success. Today, I finally hit it.
Of course, there are other ways to measure success. I've given every penny I've earned from The Single Staircase to charity and will continue to do so.
Thanks to everybody who bought my first novella. And especially the 10 who took the time to review it. (Even three-star reviews almost always caused an immediate bump in sales.)