If Adwords was a scam it wouldn't operate. Don't you think? The truth seems to lie with those who don't study the subject first, but do what they like and then get a rude awakening!
Bid high then lower bis after a cupple days. and bid odd numbers ,like .57 .27 .33 1.07 things like that... then find your high CTR keyword and lower the bid one day at a time.. Even if it says below bid , it will still show up ..
Take proper coaching specially if you are going to use adwords for affiliate marketing. There are too many professionals out there and if you capable investing in adwords then go the professional way by taking coaching as well.
When it comes to adwords, relevancy is key. The trick is to find the really high converting keywords to dominate your niche. If you can get good at that then you can become a PPC master and the sky is the limit when it comes to your earning potential
The risks are that you'll give tons of money to Google without getting anything in return. Or get banned.