I don't think that's true. If you just spend $1000 blindly on advertising, you'll get pretty much nothing back. It's not enough to make a difference. It's better to either spend it creatively, for example as I posted, buying old domains that still have traffic, or just keeping it, and using the far more valuable and scalable "word of mouth".

The general sentiment I'm seeing is not simply "don't advertise" but to make those dollars count more than buying adwords etc. can do for you. In some cases that even means doing time consuming things that don't cost money. That's all business motivated, still.