Filotto's nightly chapters are sending
The nightly reader is live: a chapter generated for one reader, verified against their known words, and mailed out. The question was how to tell whether anybody reads it.
A tracking pixel measures image loading, not reading. Apple Mail pre-fetches images for much of the plausible audience and other clients block them outright, so the number would be wrong in both directions at once. Instead every send mints a token, the email carries the title and a two-line lead-in, and the link goes to that reader’s own page. Fetching the page is the open, recorded server-side.
The cost is named in advance: the chapter text is not in the email, so a push surface became a pull surface. If opens come in under 50 percent, the first hypothesis is that this decision caused it, and the variant to test is putting the text back.