I would say "link blogging" is how weblogs started: Relatively short logs of your accomplishments or mysteries you had solved that day or just musings about one's recent discoveries on the web published on the web. It was an answer to more static "personal websites" where any new article had to justify its existence by meeting a certain threshold of novelty and newsworthiness. Weblogs got shorter and shorter, Tumblr started, then some went on to this new thing called Twitter.
