First sale doctrine - Red Box is selling it to renters who can easily sell it back to Red Box for a slightly lower price (rental fee). i.e. Red Box sells you "C

First sale doctrine - Red Box is selling it to renters who can easily sell it back to Red Box for a slightly lower price (rental fee). i.e. Red Box sells you "Captain America" for $25, you then sell your copy back to Red Box for $25 - $1.50 per day you owned it, so 3 days later it's $20.50, the rental fee being $4.50. But you only ever end up paying the difference because of tax laws.