Two years ago, while speaking at a private event held at the National Portrait Gallery, London, Instagram co-founder Kevin Systrom made a rather bold claim. According to him, the photo-sharing app had changed the way people see the world.

Very bold, you might think. But sniff and swirl that statement, as if you were tasting a glass of fine wine, and you’ll realise that Systrom might have a point.

This month, Instagram is five years old. In these five years, 400 million users have shared over 40 billion photos, averaging more than 80 million photos a day. But despite, or probably because of the staggering numbers, Instagram has maintained its original precept: that a picture is worth a thousand words.

Now the fact is that we’ve known for a long time that a complex idea, a thought or a life episode can be conveyed with just a single still image. But whereas until a few years ago, taking a picture was rather complicated and involved the expense of buying a roll of film, having it developed by a professional, and then collecting the prints, thanks to smartphones, nowadays we can take all the photos we want at the touch of a screen and without spending a cent. And that means that we have upgraded from a picture being worth a thousand words to a thousand pictures being worth a day or a week in your life.

That, of course, is a double-edged sword. On one hand, being able to capture and share a moment has made us more appreciative of the moment itself. A photo of an empty bench or a busy street may have dubious artistic qualities, yet when shared, it becomes a vehicle for meanings, feelings and emotions.

On the other hand, the ease with which we capture a moment has diluted our capacity to edit life. Not every moment is worth capturing. It’s true that a picture is worth a thousand words, but it depends what meaning those words convey. You’re more than happy to listen to a two-hour lecture or engage in pleasant conversation with a friend. But if the guy sitting next to you on the bus had to spend an hour talking about the weather, you would start despairing and looking around for an empty seat. It’s the same with photos. A photo by Andreas Gursky would command your attention for an hour. An endless stream of selfies showing every single second of someone’s life – including what they had for breakfast, lunch and dinner – would probably be dragged screaming to the trash folder.

Not every picture has meaning. In much the same way, not every picture has merit. Instagram may give us the opportunity to take and share photos. But that doesn’t necessarily make us all photographers. It’s like with words – most of us can write, but that doesn’t mean we’re all writers. So, yes, Instagram enables us to make an artistic endeavour to find some sort of beauty in the everyday. But that doesn’t mean that our every attempt to capture yet another sunset is worth the click. And while it’s true that smartphone cameras are increasingly sophisticated, the person holding that phone may not necessarily have the artistic temperament and compositional knowledge that a professional photographer has.

Beyond these arguments, one thing is for sure: Instagram is hugely influential – otherwise, Facebook wouldn’t have bought it in 2012 for a reported $1bn. In fact, such is Instagram’s influence that it has changed the way certain industries communicate with existing and potential customers – how they market their products and services.

Take fashion, for instance. Once, fashion was closely guarded in the fashion capitals of Paris, Milan, New York and London. Nowadays, fashion is what is worn on the streets: see someone on the street wearing an outfit you like, snap and share, and start a trend. It’s as simple and democratic as that.

Democracy is the key word here. It’s the rule of the popular vote – you might not agree, but if it has a majority, you have to accept it. And it’s the same with Instagram. Millions of people might want to share every single moment of their life. If you don’t want to be part of it, just look away.

The big five

For its fifth birthday, Instagram has released an official list of the top five popular accounts. Interestingly, they’re all women.

1. Taylor Swift - 49.6m followers
2. Kim Kardashian - 48.1m followers
3. Beyonce - 47.2m followers
4. Selena Gomez - 45.9m followers
5. Ariana Grande - 44.6m followers