Compact Fluorescent bulbs

In my experience, compact fluorescent bulbs generally have a five to ten year guarantee and generally do not last nearly that long. I always save the package (or at least the guarantee and anything it calls for, typically the UPC) and the receipt, and write the installation date on the base of the bulb when I install it. Whenever one burns out, I check the date against the guarantee; if it's less than the guaranteed lifetime I put the receipt and UPC in an envelope and send them to the manufacturer, who usually sends me one or more coupons for free light bulbs. They cost as much as twelve bucks a package, so it's worth the effort for me.