Go figure...
It's the best of both worlds for them. They can charge higher in store prices for an item and charge a lower price for the same item online to customers whose demand is more elastic. Since they have so many trucks carrying goods to all their stores scattered across the US, they don't have to pay UPS or Fedex to ship the merchandise to customers' homes or business, they just put the items bought online onto their own trucks and not have to add on a freight charge. The in store prices are still competitive against local retailers while not giving up online sales.
I agree it really does work out for us, we purchased several items this way and saved a lot over the “impulse buy” in the store. Now when I go in and see something I might want we go back to the car and price match it with the on-line price.
My wife is a big shopper and loves using coupons, so she makes one round trip anyway to the different stores in town. Unless we needed it that day for some reason we’ve been saving quite a lot of money this way.
One of our other problems this has helped with is getting packages delivered to our home out in the middle of BFE with a signature required. Unless I get it delivered at my work having it come to our local Walmart for pickup at our convenience is a big plus also.