The amazing thing about “Flickr” is that nobody uses the service to upload pictures.
Nobody says to themselves. I need to upload me some pictures.
Instead, they’re satisfying some other need in their lives, like showing off the new kid to relatives.
Or, showing their friends how their latest trip to Europe went.
Or, letting their co-workers in on their latest conference activity.
All of these things have to do with their life, their relationships, their everyday activities that aren’t centered on the Web, but are made much easier by it.
If we look closely, that’s what most successful web apps do: they make our offline lives richer.