Some things are better when others are doing it too.

For example, it wouldn’t be much fun to be the only person in the world with a telephone.

But the more of our friends and family use a telephone, the greater the telephone is to each of us.

This is called a ‘network effect’ – the effect that one user of a good or service has on the value of that good to others.

Network effects help explain people’s behaviour on social media networks like Facebook – it’s pretty fun because many other people we know are using it too.

But network effects can also have negative impacts too, for example traffic or network congestion, or where new users clutter or make the network less desirable.