Twitter

I personally prefer Twitter conversations to to those done Blackboard and Blogging.  This is mainly because of the ease of contacting people through Twitter.  On Twitter, one can directly contact another party in a manner that can be seen on the party's wall. But through Blackboard and Blogging, communication is limited because it can only be perfoermed through commenting on others posts.  Twitter conversations are just much more efficient than those which occur through Blackboard and Blogging. 
On my Twitter account, I followed  a company called Adar IT, which is a cloud computing service located in Lincolnwood, IL.  Many of their posts on Twitter appear to be links that promote the the benefits of cloud computing.  They are using Twitter to advertise their company.