We've been using Ocado for the last few weeks as my wife was finding it too much hassle to go to the supermarket with a toddler. It's freed up a lot of time and the service and quality has been excellent.
I hadn't noticed that they help you to remember your order and try to deliver what you normally have. Is this automatic then. What happens if you are out of the country for a couple of weeks?
Is this kind of service not common in the US then? It seems to be massive in the UK now.
It is predictable enough (and with options for "always include" and "never automatically include") that we quite often don't bother adjusting the order.
My grocery shopping have never been less stressful.