If you're trying to start a new social network/online community--whether it's for sports fans, avid birdwatchers, laser tag players, etc--there are definitely some basic features and functions that are essential in making your site successful. I don't have time to get into these details today, but it is A LOT EASIER SAID THAN DONE. Traffic does not just come because you have a cool new site, even if it does have features that no one else has.
While there are many, many, many things to consider when starting a new community, let's just assume that for better or worse, you already have decided to start one. One key to getting the word out is to make everything shareable. You have to assume that people are lazy and don't feel like sharing websites, pictures, videos or activities with their friends, so you need to make it as easy as possible for them to share content with others.
This starts with the signup process. When someone is registering AND has just logged in for the first time, they should be given the option to invite their friends. Most people probably don't use this, but you've got to take advantage of every opportunity you can. Sites like Twitter, Facebook, and Bebo all do this. Bebo is actually borderline annoying because they ask you to invite your friends every single time you log in, as you can see in the picture below.
TIME OUT - If you're tweaking your registration process, please just go ahead and give people the option to sign up with their Google, Facebook and/or OpenID account so they don't have to remember yet another password. TIME IN
If you have a community site with great pictures, video, reviews and other cool content, make it shareable. You want people to share stuff on your site with their friends, so make it easier for them. Give them the ability to share ALL content that could be shareable in a variety of ways--via Facebook, MySpace, Twitter, StumbleUpon and whatever other sites make sense in your niche. Give people the option to take popular content areas/modules and embed it as a widget on their own sites/blogs/social networks.
If you monitor users' activities you should integrate Facebook Connect (if it makes sense with they type of activity) so your users' Facebook friends can see what they're doing on your site. Maybe they'll see something like "Jane Smith just won the Pickle Picture Pose on YourCommunity.com" and decide to check out your site to see what the deal is. Bingo--that's what you want, folks.
To sum things up, the more shareable you can make your social network and its content, the better. This still doesn't mean traffic will come rushing in, but it at least sets a good framework for allowing people to share/bring in others. What do you think? If you liked this article please share it with your friends. :)