Yes, chipset coolers "work". For just a few dollars, you can move more heat off of your chips and into the chassis, where of course, you need proper airflow for your case. Some passive coolers lift the heat a bit further above the board plane, allowing for more efficient removal. Disallowing for voltage anomolies and/or savage spikes and/or other forms of abuse or accident, heat dissipation is the biggest factor in extending the life of your gear. Keep in mind, thorough heat dissipation is a commitment, not an installable part.
Plan on getting new gear in a <5 year cycle? - save your money. Rarely clean ALL the dust out of your case? - save your money. Is your computer sitting on carpet? - save your money.
I always browse the clearance bins at the various PC stores for good values and "cool" looking designs that will add to the aesthetic appeal of systems that I build.