Snapchat I actually get, since it's presenting a new kind of communication model. Facebook I get. But Instagram is just like any old image gallery, with a very rudimentary comment system and almost no features unrelated to image uploading.
You only upload 1 photo.
True, someone can dump a lot of photos one at a time, but I think that's a bit of an instagram faux pas. It tends to be that if someone is on vacation (for instance) they don't dump all their photos on instagram, they choose their one best photo, crop it, add a filter to it, and try to make it great. You don't create an album like you do on facebook. This makes the quality of what you see in your feed a lot higher than what you would see on facebook. I've been told by a few heavy users of instagram that this is what they love about it.
IG is good because of that and this pushes IG to be more about experiences over BS news and meme-macros that set a FB feed into garbage. (Depending on the person obviously.) But the incentives for interaction are very different than those with a somewhat more "traditional" social app like FB. Furthermore it lacks the update nonsense of FB such that it doesn't feel like a chore to keep up with updates. The stream passes and what you miss you miss.
Even before instagram allowed full size photos, I was using another app to allow the whole photo to be edited, and then cropping the photo after, and then printing them out. My entire apartment is decorated with framed photos that I edited slightly in instagram, but you'd never know because the edits are very subtle. (to be clear i never even posted these photos to instagram, just used the app as the editor)
If you've ever edited a photo in instagram you realize the difference between the end result and what you started with.
Giving what used to be only reserved for people with expensive software and fancy computers to regular people (and making it easy), is definitely a huge piece of it too.
At the time, about the only thing you could do with pictures you took with your phone was sync.
Instagram was released at a critical moment in history when phone cameras were starting to get good and cellular Internet was starting to get fast enough to reliably upload them.
You can't look at the landscape today and ask "Why is instagram popular?". You have to look at it in its historical context.
Source: radio interview with the founders
Instagram smartest thing they did was leverage the Facebook social graph (something much harder to do now) to integrate instagram photos as posts in the feed, so that when a user clicked on them, you ended up at instagram rather than staying inside Facebook.
Could you give a bit more details about this?
One more: https://techcrunch.com/2013/01/18/facebook-data-voxer/
Facebook took a long time to get mobile right. Instagrams simplicity, and Facebooks lack of response was what allowed Instagram to grow. And dont forget Instagram was originally more a photo hosting adoon for twitter, similar to imgur to reddit.
When you compare the amount of work required to get a startup off the ground then to what is required now. (dual mobile platforms & web & social) And the total number of apps & services. It's a deluge of information.
Then is there much change to start a service or company these days & see success? Maybe I'm getting too old, but normally I'd be full of ideas. These days I can't think of any.
I agree with the other posters on Instagram's features leading to a lower volume of higher quality content.
The UI makes the app very much about sharing photos you've taken, making content about things you have done not things you have seen on the web. And the app lets you know that those things should be beautiful. By default profiles are public, making content production more selective, and content discovery less based on personal connections.
What's most interesting to me is how the product shaped the cultural norms on the service.
If Facebook is the lowest-friction/highest-distribution place to share what's going on inside your head, IG is the place for leisure choices as identity. There's not a range of reactions, because everything on the service should be an expression of individual pleasure.
Many posts and feeds seem to focus on conspicuous, aspirational consumption (apparel, beauty products, cocktails, destinations, art galleries, etc.). It was a very smart choice for an ad-network.
Instagram became popular with the right celebrities at the right time - someone internal to the company no doubt has the user acquisition timeline and has worked out who the "patient zero" was. This sparked a wave of people joining to follow them and has effectively supplanted OK! magazine and similar. Just have a look at the most popular accounts:
http://www.dailydot.com/debug/most-followed-instagram-accoun...
There's essentially two big themes represented there, female celebrities and footballers.
The sharing and social factor was built in. Take a photo and sharing was automatic, which is pretty neat.
The name was also a huge factor. Photo Filter App 2.0 wouldn't have cut it.
It's fine releasing under a temp name, but you have to make it a top priority to change it asap. I could rant on this for long, but the long story short for B2C products it's essential. If you deliver surveillance software for governments you can get away with anything.
It's probably also a case-study in how to market social networks. Get the right people on at the right time, so people want to get on and follow them, and then post their own content.
So we use IG as our primary way to say hello, send an update, and register a Like. And then we go on FB when we have more time, or want to share a link, or whatever. But this is less and less common, judging by the relative activity I see on IG vs FB for my own connections. (And even a lot of the regular FB users are cross-posting all their photos now.)
As such it's not that great a photo-sharing UI, but it works and it doesn't require Yet Another Social Graph.
I don't know how much this is a factor in IG's continued growth in the face of Snapchat -- after all I'm talking about a cohort 30 and older. But my gut tells me it's significant.
Making it easy to positively reinforce your friends' content creation.
Fine-grained filtering of content that's relevant to you.
Luckily none of the photos were too embarrassing.
You can't enlarge an image you're viewing. Designed for mobile first, yet the size you view an image at is tied to whatever size your phone screen is. Why? I'm sure the image they are sending over the wire isn't at all as small as your screen, so why restrict it like that?
I discovered it on accident
I'd like to think the quality of their app has something to do with it. Unlike almost every mobile app I use, it's a joy to use (Android version). It's always snappy (this is huge), things always flow well, there is a ton of little detail functionality in there but it never overwhelms.
It's also great to see people's posts for a location you've tagged in your shot and compare their experience to yours. Or just find them. I know no other social network that does this so well.
It's the only social network I've stuck with and gotten any joy out of.