Twitter is the best example of micro blogging.

Micro Blogging is the newest Web 2.0 sensation. Also, Micro blogging is shrinking or limiting the size of what marketers usually write as content for his or her blog site. The goal of microblogging for SEO is to share industry knowledge and information with interested people and other microbloggers.

It depends on the peoples of your niche that which social media platform they are using to connect with each other. By the way most of the peoples are using twitter to connect with their friends, relatives and coworkers etc. Beside this facebook, Google+, myspace, Pinterest are other social media platforms to promote an online business