is adwords really that bad to use?

I had $50 free credit with hostgator but i paid $10 to activate it, I've avoided using adwords because of the things I've heard but I figured what the hell I have $50 credit and I'm only spending $1-

so with $60 I've gotten 3 sales, and with the remaining credit I still have I expect 1-3 more sales. So it will be $130-190 in return for $60. It's taking people to my landing page for a clickbank product.

So making double or more of the investment, and with the ability to track and see which keywords are and aren't doing well I would expect I'd be able to get rid of the bad ones and keep the good ones over time and get even more bang for the buck.

I'm only using 5 cent clicks as well.

I'm just wondering why it's said to be bad to use from what I heard. I'm quite satisfied to finally see money going into my clickbank. Now I know it's not ALWAYS going to give the same results, but with 2-3x the return I think it's safe to say it should at least always be profit, after all it only takes 2 sales to get back the initial investment. And with about 1200 clicks you can get at 5 cents for $60 the chances are quite high that at least 2 people will buy it.