Google have been showing clickable breadcrumbs in organic listings for some time now, and it was announced some time ago that this feature would be coming to paid AdWords ads. Today is the first time that I have seen this live in searches.
As you can see in the image above the breadcrumbs are added onto your existing display URL and are all clickable. This effectively makes your advert appear much larger, and also makes you advert appear more like an organic listing which could improve CTR.
The CPC for any clicks on these links would be the same as a click on your headline or sitelink. In AdWords you can also segment your date to view breadcrumb clicks (see below).
If you haven’t done so already, mark up you breadcrumbs using rich snippets to achieve this affect.