Social Networking is not about quantity of followers. It's about the quality of those followers. For example, I would rather have 10 people on Twitter who Re-Tweet me than 100 passive followers. In essence, having a lot of followers doesn't always equal a lot of traffic. I focus on the quality followers, in the long run it makes things much easier.
The two most important aspects of Social Networking are engaging active followers and reminding passive followers to come back to your site. By using tools such as Facebook, Twitter and 12 Seconds TV I engage your audience and keep your advertising costs efficient.
One of the most effective marketing tools I have encountered is creating a fictional charachter on Twitter. In my case, I invented Unemployed Bush. The former president has been having a tough time in this economy but is always ready to pitch a new product or television show. The satire is rapidly gaining in popularity and, at writing, has over 3200 followers. Readers tend to gravitate to a person rather than a product.
Blog Outreach is also an important promotional tool. By submitting an article to a well traveled blog or site for syndication this can improve your numbers dramatically as well as provide a strong backlink for your Google Rankings. I have had success with MSNBC, Wonkette, Raw Story, Crooks and Liars and many others