Online Supermarket

Guys,
There are so many portals which we have for online shopping, but none for the supermarket stuff like vegetables, boost, horlicks, noodles, surf excel... etc, etc, etc. Why not have one which will provide cheapest rates and also having multiple retailers on it.. like comparing rates between Fresh and More.. enabling customers to buy from whichever retailer is providing at the lowest rates. Door delivery obviously.. charge a little for that... and people who are really lazy like me would obviously get all their monthly rations online.. who wants to even go to the supermarkets!!! And advantage... as soon as the portal gets some popularity... ad's will provide in more income.. wohoo.. and door delivery can be made free... anyone interested in this...???
(Whoever is implementing this.. you have to pay me a royalty.. provided I am not involved that is.. :P)
Well one problem obviously is managing people... and lots of logistics... well can be managed maybe..