there is no greater friend to a pellet stove than faithful cleaning, speaking from experience (inspecting returned units from big box stores, (my summer vocation) there is no greater disappointment than the output from a neglected pellet stove.
its just like anything else that has moving parts, Preventative Maintenance is the key to success, follow your cleaning instructions in your manual or dvd, replace gaskets (like changing the oil in your car) is key to optimal performance in the long run. pellet stoves aint cheap (especially if its a high end model) protect your investment , abused pellet stoves not only do not burn as well or as efficiently , they can be severely damaged by neglect. ash formation channels exhaust heat into narrower spaces which concentrates that heat on smaller area. this can cause warpage and degradation of the steel or cast parts of the firebox and heat exchangers. well maintained stoves generally do not have as many expensive component issues either, a 30 % blockage of a heat exchange area of a pellet stove can result in as much as a 30% loss of heat through exhaust, ash insulates, it also can dramatically increase the heat exposure to the exhaust blower as well as the walls of the heat exchangers in the areas which are clear of ash due to velocity of the exhaust in a smaller path.
ok rant over, but trust me guys , ive seen what neglect can do to a pellet stove , it aint pretty. keep em clean and they will be there for you when you need them , abuse them , they will let you down at the worst possible moment.