Nevertheless, I'm wont to quibble the term "shoplifting." Should I lift a novel from a bookstore's shelves, they are denied inventory. But if I copy an ebook, someone's denied a quanta of scarcity.
I have written a couple novels and I'd dearly love to have a million people "pirate" copies of my work. You nailed it: obscurity is my enemy. And when obscurity isn't an issue (e.g. Stephen King) any pirated copy impacts the bottom line. You nailed it again: it's a progressive tax.
This levelling effect is a profoundly Good Thing. I sure hope the Powers That Be don't kill it off.