Did you know that Sam's Club and Costco offer free shipping on their baby diapers and wipes? That's pretty great, if you ask me.
There are so many times where I'll almost be out of diapers or wipes, and I can't tell you how convenient it is to be able to order them online in less than 10 minutes. Though I can't vouch for Costco, Sam's Club usually arrives 2-3 days after I place the order. Another plus!