People have different schedules, the goal of giving away most items is to make sure it gets to the person who needs it most. Letting a post sit for 24hrs gives

People have different schedules, the goal of giving away most items is to make sure it gets to the person who needs it most. Letting a post sit for 24hrs gives everyone a chance to see it. People comment about why they need it or will use it for in that time, then the poster can decide who to give it to after a fair amount of time.