What encoding settings does Revision3 use to get quality high but file size so low?
Your best bet for high quality and low size is 2 pass variable bit rate, but it is worth noting that the size of the video also has a ton to do with how much motion it contains and how often the scene changes.  One of the most popular modern codecs to use for such compression is h.264.

Video compression works by looking for similarities not only within one frame, but also between nearby frames.  They more similarities there are, the less data it takes to represent it at a given quality.  Variable bit rate seeks to maximize quality by using the most data where it is needed and saves data where it is not.  Using two-pass allows the first pass to figure out what the best places to use the available data are before actually making the final compression.