g1smd - 7:24 pm on Mar 17, 2010 (gmt 0)

What if a product naturally belongs to Widgets, Gadgets, and SuperGadgets on Sale categories?

Great. Link to those categories from the product page. Find more... 'Widgets', 'Gadgets', 'New Products'.

If the site uses a database and cookies, it is easy to build a separate breadcrumb trail for that visitor.

The multi-faceted hierarchy does not need to be included in the URL of the individual product pages.