Shorts-to-long-form conversion

The mechanics available are the related video link you attach to a Short, the pinned comment, the channel page and the subscription itself. None of it happens on its own. YouTube keeps short-form and long-form watch history as separate signals, a split it introduced after heavy Shorts viewing started crowding long-form out of recommendations, so someone who only swipes may never be shown your uploads.

Measure it rather than assume it. Check how much of your long-form watch time comes from people who arrived through Shorts, and expect the crossover to be small when the Short and the video share no subject.