Retro,
Normally, if you are preparing marketing samples, you do not have an order from the customer, so my answer would be "no", but let me tell you what we do ...
For our purposes, we call marketing samples "prototypes" and they are the meat of our contract review. We take the prototyping stage as the time to review what the customer wants, what we can do for the customer, and we clarify any areas that are unclear. This works best for our purposes.
Hope I didn't cloud the issue for you.
Carol