[alpineguy]

I'm of the school of thought that knowing how to effectively sharpen your chain is a necessity if you take your saw to the bush.
Chains last longer when file sharpened as well because the motorized sharpeners used in shops tend to take a bit more of the tooth each time they are sharpened. Also, using a file properly so as not to dull or damage the teeth (file) is crucial. Lots of people try to sharpen with a dull file which does not work.
Learning when and how to do rakers is also important and many don't understand this part of sharpening.
I will always sharpen with a file but I use my saws often and for an occasional user a spare chain may be the way to go as they aren't expensive.