This article misses one of the biggest value-adds of arXiv, at least in my field (Statistics): since almost everyone posts to arXiv, you can almost always find a free version of a published and potentially pay-walled paper. In the past, publishing in a peer-reviewed journal would (1) improve the paper through peer review, (2) signal the quality of the paper based on the prestige of the journal, and (3) distribute the…
On personal research, I've used it for exactly this, but since what I've seen was only preprints, I've often wondered about the final version. It looks like I'm not alone.[1] Do many or any of the arXiv papers get updates with the improvements that come from peer reviews? Is there a need for arXiv for finals or do publishers demand exclusives on finals?
[1] http://mathoverflow.net/questions/41141/should-i-not-cite-an...