Blog scholar Scott Rosenberg muses over the medium
A blog lets you define yourself, whereas on a social network you are more likely to be defined by others. [...] A blog lets you raise your voice without asking anyone's permission, and no one is in a position to tell you to shut up. It is, as the journalism scholar Jay Rosen puts it, "a little First Amendment machine," an engine of free speech operating powerfully at a fulcrum-point between individual autonomy and the pressures of the group. Blogging uniquely straddles the acts of writing and reading; it can be private and public, solitary and gregarious, in ratios that each practitioner sets for himself. It is hardly the only way to project yourself onto the Web, and today it is no longer the easiest way. But it remains the most interesting way. Nothing else so richly combines the invitation to speak your mind with the opportunity to mix it up with other minds.