I just never can find time to go to the store. Instacart isn't super cheap and I don't really trust them to pick out anything subjective but they are really great for getting the basics that I can't get delivered from Amazon.
Tip for consumers: Same tip as with Munchery: try looking for referral coupons on sites like retailmenot http://www.retailmenot.com/view/instacart.com
My family just discovered Munchery and are awfully glad we have. Both my wife and I work so having fresh, healthy food around for us and the kids really saves us. Sometimes there is not as much variety as I would like but that isn't much of a knock.
Tip for consumers: Munchery runs a lot of promotions and referral type things but you can also check retailmenot for coupons http://www.retailmenot.com/view/munchery.com