We do contact our customers... but sometimes they don't reply. I posted the question here because, to try to get a reading on what most people think would be sensible, to formulate a reasonable plan for what to do when the customer does not reply back to us.
It's not a perfect world. Sometimes we e-mail, and the customer does not receive it (and we do not know this).
Sometimes the customer replies, and we don't receive their e-mail (and they do not know).
In our shopping cart, it does show the ETA for all backordered fabrics. So the customer should be aware of the stock status even before they decide to submit their order.
'Course... we can't *force* them to read what's on their screen... but that's a whole other issue! :?