How do I model Bundled Product Subscription Facts??

Folks:

My company has a small number of products - about 15 - that we sell by subscription. Our "sell to" relationship is B2B. The businesses we sell to take a number of our products - combine them together into a package that is then sold to the end customer by subscription. (There is a fixed start date and end date to a subscription - though it may be cancelled.)

On the "what do you count?" question - we count subscriptions. Very important for the invoicing perspective - we count subscriptions - not the constituent products under-neigh. But - from other perspectives we do count the products under the subscription. How many of Product B do we have out? What is the trend? etc etc

From an OLTP perspective this is easy. Subscription 1:m Product. But how do I implement this in a star schema? Two fact tables - Subscription and ProductSubscription? Do I put a foreign key in ProductSubscription back to subscription?

Thanks