if you are willing to pay per click then Adwords is good platform for you.
What you need to have mainly is money here but don't spend too much money at first time.
Spend less money and test any products, its conversion rate....... for example if you are paying $50 for 200 clicks then you should earn at least $100 from this.
So if you are selling any products and if it is sold on 200 clicks then you have to calculate accordingly and if you are finding that there is any loss further then don't go there...