There is a site that I have been using for more than a year now to track my travel called Dopplr. It is one of more than 100 social media sites that I have signed up to try in the past several years – since a big part of my day job working in social media at a big agency is to stay current on new tools for marketing purposes. For most sites that I try, I create an account, use it for some time and then move on.  The reason Dopplr is different is an interesting story that offers some lessons that you might be able to use for promoting your business as well.  Here are just a few lessons you might learn from why Dopplr stands out:

1. Solve a unique need. If Dopplr was just another social network to allow me to communicate with my friends, it likely would have failed. The specific need that Dopplr tackles, however, is the need for any of us to be able to connect with our social network based on where we physically are. So on Dopplr you can enter the trips you will be taking, how long you will be in a particular location and who else from your network will either be at home or travelling there as well.
2. Integrate with sites your customers are already using. The best thing about the initial experience using Dopplr is that you can search for your friends through Gmail or Facebook. By integrating with sites that their users are already using, they create an experience where you don’t need to start from scratch to build your list of connections. Being able to bring in your network connections from day one makes the site infinitely more useful right away. 
3. Create an incentive to keep coming back. One of the toughest things about a new site is that often it is hard to get people to keep returning to visit the site and keep their information on the site up to date. One way that Dopplr solves this challenge is by producing a report every six months that takes all your travel and produces a very attractive PDF recap that tells you where you have been, how often you have been on the road and other trends in your travel. For a frequent traveler, this feature alone is enough to want to keep the site up to date just so you can look at your travel at the end of the year in a way that you can’t anywhere else.
4. Let users share the experience.  I have the Dopplr badge on the sidebar of my personal blog, as many users of the site also do. Through the badge, any user can share a list of their upcoming trips and allow anyone to see more details. It is simple, visual, and highly useful. As a result, it is highly likely to get included on other sites, and brings people back to the main Dopplr site. 
5. Build extended tools. Dopplr recently released an interesting tool for the iPhone and iPod Touch called the “Social Atlas” which allows you to see reviews and insights on locations from the community of travelers using Dopplr. It is a smart extension that brings the usefulness of the site to a new dimension and on a different platform, to let you experience some of the features of the site in a more mobile version – and gives users yet another reason to use the site more frequently.