Energy efficient bulbs such as CFLs tend to last about 8-15 times longer than traditional incandescent bulbs, and come with a rated lifespan of around 6,000-15,000 hours, depending on the specific compact fluorescent lamp. (Your standard incandescent bulb lasts about 750-1000 hours.)
To translate that into easier comparisons, CFL bulbs last about 1-2 years, with incandescents on average lasting about a month or a month and a half.
One thing to note about the lifespan of a CFL bulb is that it’s significantly affected by how often you turn it on and off. If if you’re turning it on and off a lot (in five minute cycles), its lifespan can be up to 85% shorter, which means it’ll last about as long as an incandescent. If you’re using CFLs, keep that in mind, as it’s often better to simply leave them on if you’re leaving the room for a short time but plan to return within 15 minutes or so.