More than a metaphor for this Marx passage: "Capital is dead labor, which, vampire-like, lives only by sucking living labor, and lives the more, the more labor it sucks.” (Both too on the nose, and ironic!)
So I donate blood as often as I can (I'm working on my fifth gallon at this point) so I always end up with Amazon gift cards for like $10-20. I put together a watch list of ebooks and whenever one of them goes on sale I give lil Jeff my blood money. Anyway, this was $4 today so I bought it