Timex says we spend 6 months of our lives waiting in line. Silicon Valley believes that number should be zero. Or at least zero when it comes to grocery shopping.

Starting with the Amazon Go stores, cashierless stores have been an optimistic look into efficiency. Amazon spurred others to think up different approaches from Smart Carts to Cashierless Snack Shacks to Scan, Bag, & Go technology. So where do we stand in 2019?