https://www.theguardian.com/money/2015/may/02/online-shoppin...
Why have the major retailers here been so slow off the mark?
One of the delivery guys even walked through our (open) door, dropped the food on the coffee table and put the VHS tape in for us.
Sadly, those economics didn't work out.
[ADDED: For example, Peapod is only available in some areas of the Northeast and Midwest]
It's been done for at least 5 years.
This service is not so popular yet (Im having hard time counting one friend who uses delivery services) but make it popular enough and Instacart and others will be out of the door.
This will be similar to LA-Fitness and other chains of gyms like Gold's Gym forbidding outside trainers for training gym members. You can only hire a gym instructor that is employeed by gym you attending.
Of course Instacart can ignore such ban and shop "incognito" but I doubt it would be great sales pitch to shareholders/investors.