If they want to claim 0 LUX, then they need to state the coverage area. Just a couple IR LEDS may give you a couple feet of coverage (good enough for a crib monitor), but with enough LEDs you can cover quite a distance. I have seen some that claim 60-100 feet of coverage, but haven't verified them.
Wayne is correct. I just bought and installed a 0 LUX BW camera with 8 LEDs and the total dark viewing range is about 6 feet. It takes a ton of LED's toget 30 feet let alone 60 to 100 feet. This camera is pretty good for a $29 dollar camera. I picked it up at Harbor Freight last week and mounted it today. You can have a look at http://18.104.22.168:8081/camera.asp
My comment about Lux ratings basically meant that if they don't mention the rating, then it is very likely that the unit has very poor light sensitivity. I wouldn't want to buy a camera that was in infrared mode 90% of the time, becuase the Lux rating was so low the camera only worked in color in broad daylight.
Hopefully someone with more money (or less of a skinflint) than me, will buy one and give us a report. It looks like a nice unit.