Maybe I'm all I see sometimes

So, as procrastination does its part in my bioinformatics final, I started reading some old dude's blog. I don't know who he was or why he is famous or whatever, but he had some interesting blogs. A lot of them were about his interactions with other bloggers and other twitterers. I started thinking about how much blog content is created based on bloggers interacting. If 25% of blog posts are links to other blog posts, then 25% of all blog posts are irrelevant, in one way. I can't tell if people do it because they are avoiding having to come up with something to write about themselves or they really want to share this idea. I don't mind them really, because they do serve a purpose, which is: you read my blog, i like this blog, therefor you might like this blog. It makes sense.
But that doesn't stop the feedback loop of reposts. On twitter, people retweet other peoples posts by adding RT before writing mostly the exact same post. I get a lot of duplicates because I follow two twitters that are very similar. It's not a bad thing because I don't want to have to follow everyone and then sort through everyone of their posts (25% of which I imagine would be retweets anyways).
Part of it is also giving credit where credit is due, and that is important. But with 25% of the internet pointing at other points on the internet, that is just so much duplicate content that it blows my mind. I was thinking about tinyurls in the same way. Almost every retweet about a twitter setting they removed had a different tinyurl link. That means there is a lot of unique links that point to the same site.
It just seems like a lot of space that isn't unique.