You need to cover all your bases, Twitter, LinkedIn, Facebook, YouTube to name but a few, the advantage you now have is that you are using a single source, your website blog, so you already have the content that you can point all of these towards (thus reducing your overall workload).
Now, analyse your response, look where you get the most activity and give that some focus, however activity is often confused with results, take a second look. 10,000 followers on twitter, but only 100 clicks, maybe one purchase. 1000 people in your LinkedIn group, with 50 clicks and three purchases. Look to where your results come from and give it some real backing. You maybe surprised as to where you get your results.
References and Inspiration in 7 Habits of Highly Social Media – Intro