It probably depends what you are selling. I think you have to be wary of any blanket statement like the one you quoted.
Anything that may or may not be in stock and that I urgently need, like appliances or computer equipment, I always order by phone, because the person on the phone can tell you when it will ship and how many days it will take. They do not as reliably give you that information at a web site or by email.
Also, whenever I am ordering anything that costs more than, let's say, $200, I want to speak to a live human being and get their name as well as an order number.
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