>>scolle+(OP)
I wasn't advocating one way or the other. It was a genuine question. If 10 orders per hour is typical, that is $50/hr on top of what they are already making. Even just 4 orders per hour is an additional $20/hr. That could put the total pay to at least $30/hr? I think maybe that's fine for a luxury service like this, but that kind of pay probably shrinks the market for this service considerably, I can't imagine the margins in this business are very high.
Personally, I would be fine with paying $5 extra per order of groceries, but I'm not a user of services like this.