Are your drying cycles increasing in length? Do you frequently re-start the dryer upon noticing that your clothes haven't fully dried?  Blocked dryer vents severely reduce the efficiency of your dryer. Regular dryer vent cleaning ensures that the dryer is functioning correctly, leading to shorter dryer cycles.  A clogged dryer vent can prevent your dryer from running on optimal efficiency, leading to dryer times upwards of 30-40 minutes.  Who's got the time for that?