Businesses big and small have jumped on the social media marketing band wagon. Managing an account on every single social network is time consuming and not effective for smaller businesses. It is important to realize which social networks your demographic uses and how to effectively use it. By targeting specific social media networks and ignoring others, you can dedicate your time (and budget) to the most cost-effective marketing channel.
Another important thing to consider is how much content to share and how often. If you want to distribute a lot of content to your followers, you may want to use Digg, RSS feeds, Delicious, Stumble Upon, or your blog. If you plan on giving short updates or holding contests, you will want to take advantage of Twitter's abilities. You should also set up these networks to your smart phone or mobile device so you can send updates to your followers no matter where you go.
There are also many services that can aide in managing these social networks. I would recommend checking out TweetDeck and HootSuite. These services allow you to manage all of your social media sites at the same time along with scheduling updates. You can set timers to when you want your updates to be distributed so that you send out the exact message at the right time, even if you aren't on the computer.
There is no question that social media is a great tool for marketing. I recommend that every business, no matter the size, take advantage of the tools associated with social media. However, it is important to always be aware of change and what is on the horizon. While social media is popular right now, we know technology is changing as we speak.
For more information, check out the following articles:
http://www.problogger.net/archives/2008/04/08/how-to-target-the-right-social-media-sites/
http://traffikd.com/resources/35-must-read-articles-for-social-media-marketers/
http://www.capecodseo.com/social-media-no-brainers/