One of the great benefits of online publishing is but a side-effect of the overall project: the constant creation of a pool of data that contain information about how research is accessed, used, discussed, and cited.
Martin Fenner, the technical lead on PLoS Article Level Metrics project, has scooped up some of that data and painted this pretty picture of, well, browsing. The big square captures the population of people who have surfed over to an HTML version, and with each smaller square you can see that the number of people who found something relevant decreased, until you end up with the small group chattering about an article on blogs, Facebook, or citing it formally in another paper.
A few years ago sociologist James Evans published an article in Science warning that the increased efficiency of electronic search may narrow the range of papers researchers found, which may "accelerate consensus and narrow the range of findings and ideas built upon." The graph above is too simple to outright undermine Evans' point (we don't know, for example, how this sieve compares with offline searching, nor do we know whether researchers are finding papers far afield from their own), but it's certain from this that online searching still requires inefficiencies, and that people continue to browse the HTML and hone in on their desired finds from there. Additionally, Evans could not have anticipated our social web in 2008, but part of the inefficiencies captured above may be that we don't read the web (specifically, PLoS ONE) only through search, but through sharing, blogging, tweeting, etc. These may bring researchers to papers they would not have found in searching, and result in the serendipitous connections Evans revered.
And also, props to PLoS ONE. Fifty-three million-odd pageviews for some 37,000 papers is no joke. The number of downloads and Mendeley readers are likewise impressive. If there's any real take-away here, it's that their open model is attracting tons of readers and discussion -- both on the content of their articles, and, now, the shape of their sieve.