Ubercart

I believe the multiple breadcrumbs is intentional. Our thoughts were that most products will be in a few (three or less) categories at most. Given this assumption, there are two benefits to showing all the breadcrumbs. One: the breadcrumbs show the customer other categories with similar products which the customer may be interested in. Second: the additional breadcrumbs provide additional keywords which search engines can use to better rank the product page for relevant searches. (I never support keyword stuffing, or designing a site / page for search engines at the expense of human readability, but good design often benefits both humans and search engines as described above.)

That being said, I see how this design may not be the preferred method for some sites. Perhaps the solution is to give the site administrator a site wide configuration option of multiple breadcrumbs or only showing the breadcrumb that the user followed to get to the product. But then there is still the undefined case of a customer browsing directly to the product page. In that case you could "just pick one" or you could have the site administrator set one as default when the product is created. I vote for "just pick one." It seems to me that the coding effort to enable a primary trail and the administrative effort to set a primary trail for each product is not worth the benefit for this trivial case.

If this is agreeable to everyone, we can make a feature request for it and put it in core. What do you think?

Andy