Forum Moderators: rogerd
Another thing, what is a realistic expected amount of users for the first week, month, 2 months? It's hard to tell if the site is doing well without any reference point.
Then Flickr goes further and provides APIs for other sites and software to integrate with their system to provide further usefulness. One good example of this the Eye-fi wireless storage card for digital cameras that removes the need for users to even connect their cameras to their computers. The SD card stores photos until a wireless router is in range and then automatically connects and uploads the user's photos to their Flickr account.
You will have great trouble in creating a community because its already been done, people are established in other content rich sites.
Instead for fighting in a crowded arena you need to specialise in something new. For example one of the nicest digg clones I have seen is Dzone, focusing on articles for programmers.