By cleaning out the lint, the air flowing into the dryer will circulate better so it can continue to blow out with full force, so the process is shorter. Wow. What a aw-ha bit of information.
Wondering how often you should do this? Hairdressers do it almost daily as their hairdryers get used much more but for the average home use, once a week is recommended.
If the grooves on your hairdryer are small, I recommend using an old toothbrush or tooth pick. I will warn you, it is a bit tedious so don't attempt this on a morning you have to be out the door at a certain time. Once you have all the lint/dust cleaned out, take a damp cloth to wipe down the hairdryer.