A FlipBook is a special type of PDF today that allows you to flip through the pages like you are reading a book. There is a product out there that allows for these to contain animated gifs, embedded videos, opt-in forms and links so that you can create a more interactive lead magnet and these are currently converting at 2x the standard lead magnet approach for many affiliate marketers. It would be very nice to have native FlipBook support inside the funnel builder, which would eliminate the "download this pdf" lead magnet and result in more control of the user experience and higher conversions.