I wonder why this failed? I've seen infinite scroll work on some major websites, Facebook and Twitter, but then perhaps it's related to search only? FB and Twit

I wonder why this failed? I've seen infinite scroll work on some major websites, Facebook and Twitter, but then perhaps it's related to search only? FB and Twitter are loading a feed, a search page should give users what they expect to see, not randomly see more elements pop on screen, perhaps?