Pick one and press Start, then click Next › to step through it.
Pull's per-day total landing several times higher than push's, and the crossover sitting far below the forty feed-opens a day the scenario assumes.
Why a read-heavy fan-out is a push (fan-out on write) problem: you precompute each feed once and read it cheaply, instead of reassembling it on every open.
Charge push its writes per post and pull its fetches per open, roll each into a per-day total, then compare — and drag the crossover to find where the winner flips.