Last year, I bought some tires at Walmart using their ship-to-store program, and got them installed at their auto center. Here's how it went:
Ship-to-store is the repurposed layaway counter, and isn't actively staffed. Instead, you ring the associate using a kiosk.
No associate showed up. Had to ring at least twice. About 15-20 minutes in, an attendant working the floor asked what the deal was, and I guess he tracked someone down. I'm not sure if the notify attendant functionality was broken or the associate was at fault, but if that's the typical ship-to-store experience, I'll pass. Wheeled my Walmart.com-wrapped tires to the auto center, and they overcharged me $20 for installing "third-party" tires.
Ship-to-store could work if you implement it like Amazon once discussed using lockers--you come in at any time 24/7, obtain the contents of your locker, and leave. Retail employees only add negative value, and should be kept as far as possible from fulfillment.