Yes, if your blog happens to be “myteenramblingswheretheuniverserevolvesaroundme.blogspot.com”. Not so otherwise. Heck, you have what 5000 friends on Facebook? Me? Even my wife doesn’t read my blog! :-) But still, of the 100 or so unique visitors I get per day, a good 10% come for one single post: a post I made 4 years ago (quoting Noam Chomsky).
Yes, a book is different from a blog post, but only in the way a book is different from journalistic articles, etc. There is so much baggage attached (by curmudgeons :-)) to every new technology: blogging, Facebook, Twitter, etc. But while all of these criticisms are expressed as criticisms of the technology, they are almost always criticisms of the people using them and the way they are using them.
Second, so what if the post only lives 5 days? It still goes out in the world and people still do react. That’s still worth something!
I am sure the CIA is subsidising more than one blog today :-).
—ravi