Whether it's asinine antics in the Big Brother house or ultra-violent video games, you know any form of entertainment has finally gone mainstream when universities start offering courses in the matter at hand.
The latest previously niche fad to join the list is something we've encountered several times in the past – comic books on mobile phones.
Creating Japanese comics, or manga to give them their proper designation, is the focus of a new course at Kyoto Seika University in western Japan, where students recently presented the results of their first year labours designing electronic versions of their favourite works.
Considering that the Japanese market for mobile manga grew by 80 per cent last year to be worth ¥23 billion (£107 million), it's easy to see why 30 people have already signed up for the tutorials led by some notable graphic artists.
Clearly, the market is already well established, but why is it promising such riches for the creators when printed manga can be bought in every corner store?
We interrupted one fan spotted reading e-manga on a train to ask why. Tokyo-based shop assistant Hiromi Gomi, 19, explained: "Manga on a phone are appealing for three main reasons – they're easy to carry, cheap and interactive."
While the first two points are obvious to anyone who's paid around £3 for a telephone-book-sized printed comic in Japan, the latter underlines exactly why experts are predicting the art form has potential to make it big overseas.
Many of the comics on display at Kyoto Seika brought a little extra to the experience by using a phone's capabilities intelligently. That can be anything from a brief vibration representing on-screen action to an audio clip at a key point in the story.
Whatever the draw, chances are we'll all be indulging in a spot of manga at the back of the bus before very long.