What else can you save?
If you rent movies online there also no late fees or shipping costs and you can keep the movies as long as you like. You just need to return the movies (depending on the rental plan you are on) to get the next one on your list.
New releases also cost more in gomovies online store to rent and this is something that doesn't apply if you rent movies online. Some companies don't charge you extra for DVDs in Blu Ray format.
Another less obvious cost advantage when you rent movies online as opposed to in store is the saving on travel costs if the store is located some distance from you.