Oh, I'd agree, but I'm not sure if it is complicated; LJ appears to be trialling it on some Comms:
http://community.livejournal.com/frankandmeme/
http://community.livejournal.com/lj_photophile/

And seems to have a nice simple implementation, it's definitely keeping track of who clicks and showing a display, but I can't see how it's actually working, nor can I find the Releases or Chagelog when they introduced it :-(