I don't want to give the impression that YTB is the only MLM company out there in the travel business. They are probably the largest, and from what I can see the most vocal. They are also publicly traded, so they are also a little more "in front" so to speak.
But, each one of these MLM companies has their own little tweak on the program. They all tout the discounted travel, and more often than not the marvelous compensation package. This package (for most) will never materialize.
Here is a Coastal Vacations "video". It apparently was recorded off of a television by a camcorder so the sound is way off and the clarity not so good, but if you watch, take note of how confusing the compensation program is as well. They are all similar--equally confusing.