Integration of Google Maps and Local Stores for grocery pickups!

Idea is very simple, integrate different grocery stores nearby on Google Maps, from your locality, from where you buy your daily necessities. This can also be used to maintain a ledger so that if you leave your room to pickup some specific grocery one store can mark if they are out of stock of it making it easier and save some time wandering from store to store.
Since grocery store owners won't be hiring any delivery staff( if they don't want to) they can serve their customers better. And even if they provide home delivery they won't have to make a big investment as the customers are either from the next building or a block away.
There are many other integration that one can benefit from it, not just the customers but also the shopkeepers and owners.