This could be useful to us. We sell attendance to events as a product, but there's no linkage between the event and the product. In our case, we have just 9 or so events over a three-month period, so it's doable to set up the 9 products. If one could purchase a place at the event it would be more attractive and manageable. Even if you could just tie indicating attendance at an event to purchase, that would help us (but probably not the original poster).