I'm going to predict that this will never be that big. I think food may be the one thing that is just easier to go out and buy. Some people may remember the 'big peach' guys about a dozen years back? They tried the same thing in this fairly high income local... They failed. I think they eventually sold out to another company trying the same, and then they failed as well. At the time, I thought it was a great idea and even wanted to invest in them. Yet, I never used the service myself. I guess that says it all.
Vons has been offering the same thing on a small scale around here for years. I see some people around me using them, but it is not a huge thing.