Think of #pay as a filter on the wider porn caption caption archive: same submission pool, but slimmed down to the exact register you searched for.
You'll see fresh drops from the last 48 hours, veteran porn caption classics that still pull views, and the tag-graph neighbors people click through to next.
Because #pay is tag-locked, the recommendations under each post also stay in the same lane, which means fewer 'that wasn't what I wanted' clicks and more time on the actual fantasy.
Every visit reshuffles the sort weights slightly, so the same #pay archive rewards repeat trips — the top of the grid tomorrow won't be identical to today.