A mattress is important because it is here people relax at least 30% of their life. It is therefore important that you clean it regularly. Would you want to put your face on a surface full of termites? For health reasons, cleaning is quite important. After all a dirty mattress could be the breeding ground of dust mites and other allergens. Odors would make you uncomfortable and hinder you from having comfortable sleep too.
 
For standard maintenance, it would be advised that you flip your mattress and vacuum it at least every 6 to 8 weeks. But then if you have children you would have to learn more deep cleaning techniques. For instance, you should get rid of urine stains and odors. Otherwise you would not feel comfortable in your bed at night. The trick really is to blot the wetness using a dry towel. To make this step more effective, however, someone heavy must stand on the towel to blot more of the urine. You may only stop when no more urine can be extracted from the mattress. Then spray some enzymatic cleaner dedicated for urine on it. And to help get rid of the odor, you should try putting a little baking soda on the spot. Let it stand there until the odor is removed. You can then vacuum the mattress.
 
If you are a smoker, you would have to contend with the smell of the cigarettes on your mattress. What you should do is put the mattress outdoors on a sunny day. Spray some odor recover then. Bring the mattress in and this time put some baking soda. Let it stay there until the odor is removed. After that, vacuum the baking soda.