Hello Phil,

Answering your quesitons....

Not sure what you meant by "instance". If, by that you mean an instance of
one ad being in one magazine for one month, for better or for worse my
structure does not have that. And so such a record would not exist or be
created. All answer are derived from looking at the purchased "block" of
ads in a particular magazine.

The one table would hold it for all of the magazines. The "ProductID"
field would identify which magazine the OrderItem is for.

Hope that helps a little.