/img/reddit.gif = 197
/img/instagram.gif = 463
/img/tumblr.gif = 833
/img/skype.gif = 1024
/img/twitter.gif = 3935
/img/dropbox.gif = 11574
/img/google.gif = 33333
/img/youtube.gif = 46333
/img/facebook.gif = 52083
/img/email.gif = 1666666
Those are the number of actions per second per each service. I am surprised that for an audience such as hackernews that no one knew to read the source
elinks -source http://onesecond.designly.com/ | grep "\/\w*\.gif\"\ data-count='[0-9]*'" -oIt's one thing to know how far it is through the Hundred-Mile Wilderness, but it's another thing to experience it and to know for yourself how far that is.
It normally takes me a moment to understand that 3697893 is three million and not three hundred thousand. It's even worse if that number keeps changing. (Perhaps it's just me because I'm mildly dyslexic.)
Cool project though!
They do a straight multiplication so the number doesn't appear to be pulled dynamically from any of the sites. I.E. You can take the total and the time you've been there, do a little division and get the number per second without having to count.
EDIT: Also if you refresh the page near skype, reddit or any of the others and wait 1 second it'll show you the rate before it's modified by the time you've been on the page.