We've seen this on our site, which is heavily search focused. Despite having an "advanced" search menu right next to the default search bar in our header, essen

We've seen this on our site, which is heavily search focused. Despite having an "advanced" search menu right next to the default search bar in our header, essentially no users take advantage of it (and we're dropping it as a result.) Faceted search is clearly being used by people on sites like Yelp and Amazon but they might not realize it (and might not think of it as "advanced search".) Unfortunately it's harder to add faceted search to a general purpose, free-text search site like Google, so users may not take advantage of it as readily when doing those kinds of searches.