"A very bright 1080p projector built for living rooms you can't black out."
The '4,000 Lumens' figure means this projector is bright enough to produce a usable, large image in a moderately lit room, where a typical 'home cinema' projector would look pale and washed out.
This is for someone who needs to project a large image for sports or TV in a living room with windows and cannot achieve blackout conditions. The 3LCD technology is also a good reason for buyers who are sensitive to the 'rainbow effect' common on competing DLP projectors.
Anyone with a dedicated, light-controlled viewing space should prioritize a projector with better contrast ratio, even if it's dimmer. Buyers seeking maximum detail can find pixel-shifting 4K projectors at a similar price point if they are willing to trade some brightness.