need help understanding vegas tournies

[winchips]

Heading to vegas tuesday and may play some tournys.
I used this to find some to play in:
http://www.lasvegasvegas.com/poker/tournaments.php

many tournies say 50+0 or 70+0

Does this mean the house doesnt take anthing at all? or am i missing something. I guess they mat do it just to get you in their casino, but it surpises me.

Anyway off to vegas tues - sat :-)

Thanks