I find I save money buying books online. I usually shop at Indigo and the online prices are cheaper than in store prices.
As others have said, it can help with the impulse purchases.
I think I'm going to start shipping friends and relatives gifts directly from stores since as Tricia mentioned it is costing more to mail things. It will also make it easier to send edible gifts and flowers to people who don't live anywhere near me!
Bookmarks