I have a 6 month old MacBook air. I use it for my online business at least a few hours a day and don't have a wireless mouse so I click the trackpad a lot. Lately it isn't always working when I light tap with my finger. If I use the pad a lot does it break easy?
Is it possible something got stuck or is otherwise jamming the trackpad? Best bet may be to have genius bar take a look.
On older macbooks there was an physical adjustment you could make on the trackpack (open the case, remove some stuff, adjust screw). And we had a problem with the battery swelling which caused the trackpad to stop working (essentially prevented the "click" action, as it was pushing the trackpad up).
That much use shouldn't break it. If you can part with it for a couple days, you may want to have Apple service it (it should still be under the 1-yr warranty) just in case the trackpad breaks completely.