If you are not doing trials you can update 3 times a week and keep people happy.
With trials 6 or 7 times a week if you want to keep the conversion from trial to full month up.
Our sites update daily with new video and 25k+ pictures..
http://www.monstercockmadness.com
http://www.bustyamateurboobs.com
Other sites:
atkingdom.com
scoreland.com
twistys.com
karupspc.com
The list is rather long to be honest.