How immediate is "right now"? If you have to drive 45 minutes to the store and back, is that "right now"? If Amazon can deliver it two hours from when you place your order (which they already do in some cases), is that "right now"?
If you've got to drive 45 minutes just to get to a Walmart, Im not sure you live in a population center large enough for Amazon to offer two hour delivery.
Lol, it can be an hour or more depending on traffic to go to Walmart from Seattle, and your choices are either going far north, or far south. I only ever find myself there when I need a cable modem at 2am, and especially then its always a terrible experience. If I can be out by 4am then that is a quick trip!
I live in Downtown Seattle and it would take me at least an hour to get to the nearest ones unless it was maybe 3 AM and there was no traffic.
I also see a trip to the store as a chore, but I see Wal-Mart as being uniquely positioned to do 1-hour delivery from their own stores - which are essentially localized warehouses across most of the U.S.
If you have a 90-minute round trip to the store, odds are Amazon won't be delivering anything in 2 hours.
Less than an hour. I think that is the threshold between "I'll order this on amazon" and "I'll get it at Walmart."