With respect to cables, my understanding is that the coiling/uncoiling process makes it necessary to re-form the dielectric. Dekay noticed this recently with a set of cables that had already seen extensive use- after shipping they needed to be burned in again.
componet/cable burn-in
I understand the changes involved with component burn-in but wonder why it is not possible to purchase a component and especially a set of cables that are already to perform right out of the box? I'm running in a cd player right now for a week day and night. It's a cheap one so I can understand that the manufacturer can't afford to do this but with the prices for the cables on the market, what's the excuse? This burns me in!