CFL bulbs are a false economy in terms of dollar value and energy efficiency. First of all, it's not enough to calculate the lumens produced per Watt consumed during use. You have to consider the entire life cycle of the bulb. Manufacturing CFL bulbs is much more energy intensive than incandescent ones - and each bulb has its own mini electronic ballast. The mercury in each CFL is bad enough, but consider the manufacturing process of all of those little circuit boards. Plus, when one dies, if you are a good environmental citizen you don't throw it out. So what do you do - drive somewhere to dispose of it? And what does the person you brought it to do? Ship it to china on a boat to be "disassembled" - and do they recapture the heavy metals or just take the pricey bits out and chuck the rest in their own landfill? You also have to consider functional life. These packages with their sky high life ratings are selling misinformation. CFL bulbs get dimmer over time, and when they fail completely, it is not a simple matter of a filament wearing out - any number of parts in the bulb can fail and cause the entire thing to stop working. Worse, these ratings are based on continuous use - every time you turn one of these off-and-on it shortens the functional life. So you can only trust the quoted lifespan under perfect conditions and only if the bulb is never turned off. CFL makes some sense for applications where the lights are on all the time. For most houses though, it is actually a better environmental and financial choice to stick with incandescent bulbs and simply turn the lights off when you don't need light!