These numbers are quite interesting. Particularly the ratio of submissions to published papers. Am I right in thinking this means you are rejecting 60-70% of all submissions? If so it would be interesting to know why this is so. This seems to be a higher rejection rate than some low ranking journals.

Obviously the PLoS ONE editorial guidelines are quite clear but for more than half of the papers submitted to not reach the standard of 'publishable' seems quite suprising. Is it a result of lots of submissions by cranks, or are there that many genuine submissions that fall below the bar? Or is it just a result of the way the journal is growing?