I found this on the Progressive Review. Instant run-off voting makes a LOT of sense, and this clever ad from England puts in pretty clear terms why:
We’ve long advocated instant runoff voting and now Britain is voting on adopting it (over there it’s called alternative voting or AV).
This is one of the best graphics on the topic we’ve seen. (FPTP is “first past the post” or the way most American elections are run)