Have you ever done game programming? Here's one example: multimedia iOs apps, like games and enhanced books are severely memory constrained. Every kB saved can make a difference. Even in a large console game, memory becomes an issue. Most AAA games have hours of prerecorded music, sound effects and voiceover. If console developers can squeeze their audio by an extra 5%, without degrading the audio too much, that makes a big difference to the the memory footprint (or the amount of audio). I do audio at a flash development company that works with giant media corporations and 48kbps mp3 audio embedded in flash swfs is more common than you might think, due to the desire to keep loading times down.
Also, one of the biggest uses of AAC is within mp4 and quicktime movies and video streams. I'm betting that the average 360p youtube video is probably encoded at 96kbps aac. Another use might be high participant video/audio conferencing where one has to download multiple simultaneous streams over the same connection.
Another example might be streaming to remote locations in developing nations. I'm sure there are countless other applications.