Does anyone buy groceries online? Are they cheaper??

So I was just wondering, does anyone buy groceries online? I know that there are a few sites on the net that has some pretty descent prices and I was thinking about starting to do that here pretty soon. I am tired of going to the store just to find that the item(s) I need/want are out or off sale or whatever. I would like it so much better to have things delivered here to the house instead of getting out wasting time and gas to find out the stores are out.


So if you buy some of your groceries online, share with me please what sites you use and I will look into them.