Hey i think social networking like facebook which is third rank by alexa and other networking site like myspace ,orkut,hi5,bebo,etc.,are good for marketing because they have great traffic but how to get traffic from them.
I don't know about myspace but Facebook is good for me. I receive good amount of traffic from my FB Fan page.
First off all you will need to build those account i.e. get more friends, followers etc to your page. You can even try buying friends followers etc, the more better traffic you will get from them.
Other than facebook all the sites you mentioned will take atleast 6 months to get traffic to your site. However Facebook is the only networking site where you can get instant traffic to your site if you play it smartly. I am sure you must be having an account on facebook by now, make sure you add not more than 30 friends everyday from your niche on facebook. Then after a month, when you have good amount of friends, start a fan page of your site then share and tag your friends there, you will automatically get more and more eyeballs to your fan page. These eyeballs will eventually be converted as traffic for your site, if you have an attractive image and catchy titles posted on your fan page wall. Hope that helps !!
I always tell people that you need to build trust and credibility amongst your FB followers first before you can expect any type of traffic from FB to you. Once that is established and you have a good fan base and decent "likes", it will become a marketing tool at that point. I have known people who set up FB pages expecting thousands of hits to their main site instantly lol.
For the Marketing FB is one of the Best site, but not the MYSpace its completely Social networking site, not good for Marketing. Choose FB
I don't know about others since i have never used them but i am sure that they won't help you to get good piece of traffic, so i think Facebook will be better option for going with.. Good Luck!!
Facebook is by far the biggest and most influential social networking site, it help to get lot of targeted traffic at free of cost. In Facebook, you'll notice that many of your friends will say that they 'Like' a certain page or group. If you have an interest in that same topic, you'll most probably visit that page as well. This is especially true if more than one friend 'Likes' the same thing. Another way you can make use of Facebook traffic on your own website or blog is to place a Facebook "Like" button on your pages/posts and also a Facebook comment section. There are Wordpress plugins that do this for you, or if you have a website, simply go to the Facebook Social Plugins section on the Facebook website for instructions on how to do this.
I haven't really used Myspace much but i think facebook is better. Twitter is also another social network that helps in online marketing.
Don't about Myspace , bebo and others... I am using facebook or twitter for marketing and I must say both are the nice or effective way of marketing.