> "You could argue that theatre, cinema and opera also rely on getting and keeping your attention. Nobody says they're addictive or "gamified"."
Theatre, cinema and opera are experiences that are best appreciated in small doses. Television, on the other hand, is something I'd class as addictive. Wouldn't you?
> "The reason I have trouble seeing the "gamification" aspects of Instagram is that there are none. This idea that a photo sharing site is designed to be like a drug exists in your head - every argument you make easily applies to many other kinds of business that nobody considers addictive."
You have to separate the intention from the result. Did the creators of Instagram intend to create, as you put it, "a drug"? No. However, they did intend to make it a popular platform for advertisers, and advertisers are clearly interested in getting as many eyeballs on their products as they can, and the more the creators of Instagram can do to make their site sticky and drive engagement, the more their company will grow. Whilst their users are of strategic importance, their most important customers are advertisers. Increasing the userbase only makes sense if there's a corresponding increase in advertising revenue, they can't run on good will.
To give an example of a feature that increases the stickiness of Instagram (note that I didn't use "drug", that was your term), I'd suggest Instagram Stories (a feature inspired by Snapchat).
http://blog.instagram.com/post/148348940287/160802-stories
The idea being, you have to use the app every day otherwise you might miss something. Previously, you could dip in and out of Instagram and not miss anything. With Stories, that's no longer the case. Also, as well as viewing the stories of others, creating your own 24 hour story also encourages much more use of the service. What's opera's equivalent of Instagram Stories?
Let's move away from Instagram for a second to consider other players in the attention economy. News organisations are most definitely in this space as well. The rise of sensationalist, clickbait news articles, even by news institutions that were previously above such behaviour, is a clear indication that we're in an era where attention is something that's harder to earn. Have you noticed this trend or would you like some examples?