Location-based breadcrumbs help the user understand the websites structure by identifying your current page and linking to pages above in the hierarchy.
Home > Services > Book Kits
The structure is pretty obvious here. The user is on the Book Kits page that resides under Services and Services resides under Home. This type of breadcrumb supports usability, findability, and accessibility to improve the user experience. Findability is an important part of how I define User Experience and it often gets left off of many User Experience diagrams.
User Experience Honeycomb by Peter Morville. Used with Permission.
Path-based breadcrumbs are pointless. I'm not sure why they were ever invented, but they essentially create a trail for you of every page you've been to on the website.
Home > Services > Book Kits > About Us > Home > Contact Us > Catalog
There is no structure here that helps navigation. It duplicates the function of the back button, it confuses a user who might want to reference where they are in the website hierarchy compared to home, it displays a creepy tracking history trail is not helpful, and it confuses search engines by showing duplicate content links with endless variations for robots to find.
Attribute-based is what every good e-commerce website should have implemented for filtering and faceted searching. This is the most complicated type of breadcrumb to implement correctly because with search engines it is extremely important not to portray duplicate content. So making sure you setup correct redirects (.htaccess or proxy level) to ensure the order of the filters doesn't matter is critical.
| Fiction x | Adult x | War x | History x
When using Attribute-based breadcrumbs it may or may not be helpful to include Location-based breadcrumbs. In the next example, I've mixed Location-based breadcrumbs and Attribute-based breadcrumbs. The first 3 items are Location-based and the last 4 are Attribute-based.
Home > Services > Book Kits | Fiction x | Adult x | War x | History x
Breadcrumbs aren't aiding the user significantly and taking up valuable space.
Home Button: 1,555
First Tier: 190
Second Tier: 0
Total Users: 235,986
There is an article from Google on Structured Data and using breadcrumbs in searches which should put down all arguments about breadcrumbs being dated and pointless. They use structured data and breadcrumbs to directly impact search results allowing user to not hit the desired landing page, but navigate to a subset of that page whether it is location or attribute based. If the big G uses it to help you tailor searches better for your audience, you better get on board.
While the 2009 study from Jakob Nielson and Kara Pernice is ancient in regards to breadcrumb tracking, the large amount of data there is definitely one reason we still have breadcrumbs. The book Eyetracking Web Usability summarized the data and concluded that "People look at breadcrumbs 30% of the time". Now realize that number has changed over 6 years, but the study combined with Google using structured data and you have a really hard argument to discredit.