PURE SOCIAL NETWORKING SITES DON'T focus on a particular type of content. That is, they are not just for photos, videos or blogs, though they usually have the ability to create or share all those. The two big-hitters in this space are MySpace (www.myspace.com) and Facebook (www.facebook.com).
MySpace's demographic skews very young, and its primary (but not exclusive) draw is music. MySpace offers a rudimentary ability to customize a profile page with graphics, videos, a blog, a list of friends, and a few other things. Because of the fairly limited, user-unfriendly nature of the customization ability on MySpace, and because most people on the site are not Web designers, are not artists, and apparently lack taste, most of MySpace is ugly. The main point of MySpace is to convince as many total strangers as you can to be your "friends." The more friends you have, the more "cred."
While it's possible to use MySpace as a tool in the context of social network marketing, unless you spend a lot of time (or pay the fee to become an elite member, for a really nice-looking profile and other advantages) MySpace is basically worthless in attracting good leads or driving quality traffic. That's not to say that it can't be done, and I'm sure someone reading this is going to try and prove me wrong.
My recommendation is that you set up a MySpace profile, populate it with some relevant content, get a few hundred friends, and use it every once in a while. But it probably isn't where you should spend most of your time. On the other hand, if your dealership focuses on youth culture (stunting, freestyle MX, etc.), MySpace can be a great fit, especially for things like videos and getting the word out for any stunt shows or other exhibitions you may be putting on.
THE RISE OF FACEBOOK
If MySpace is sort of the sinkhole on the Web, what's better? Well, it looks as if Facebook may be the new king of the Web. Facebook seems to skew more toward college-age users, although recent reports indicate that one of the larger areas of growth is women in their 30s. One area worth taking advantage of on Facebook is the Groups. While perhaps not as plentiful or as populated as other groups sites like GoogleGroups or Yahoo!Groups or Yahoo!360, they are within the Facebook ecosystem.
Facebook seems to be pursuing a strategy of becoming an operating system for the Internet. It has something to do with the ability to create and deploy widgets and applications that use the technical underpinnings of the Facebook platform (known among the pocket-protected as an API or application programming interface). What this all comes down to is that not only does Facebook have a lot of attention pointed at it, it's also developing a strong technological underpinning that will allow it to evolve and grow. Facebook users are of a decent quality, the site has a lot of good social networking functions, it has technology that can be leveraged to create custom applications or features, and it appears that it's going to be around for a while. If I were to focus on one site, it would be Facebook.
IN THE WINGS
So what are the up-and-coming sites? There is a lot of buzz around bebo (www.bebo.com). Another site just launched to the public, called Pownce (http://pownce.com), is all about sharing stuff like videos, photos, invites to events, and so on. Because most of the buzz and money is stampeding to social networking sites, there's going to be a lot of new sites coming out. And because of the way the Web works, each new social networking site is going to rip off, or at least riff on, what's good or what works on existing sites, and ditch the stuff that doesn't work.
Another site is LinkedIn (www.linkedin.com). LinkedIn is based on the six-degrees-of-separation idea with a business and employment networking focus. It's a stunning way to get in touch with people you used to know, and get to know people you need to know by way of people you know in common.
A good place to go to see what's out there in the social networking space is this Wikipedia page: http://en.wikipedia.org/wiki/List_of_social_networking_websites.
To leverage these and other social networking sites, you need to participate — a lot. I've read enough case studies, and have heard enough presentations at Internet and e-commerce conferences, to know that social networking can pay dividends when it's used right, and most of what makes it right is constant, dedicated participation. I can easily make the case that just the social networking aspect of Internet marketing (social sites, forums, blogs, etc.) requires at least one dedicated person at your business. You need to have someone who does nothing but come up with good ideas, and has the time to devote to executing them. It's time-consuming, but it can pay off.