The real key is to budget yourself. Let me explain, if you are promoting a product through PPC and your profit for each sell is $15.00 then you don't want to go over .12 cents a click for a conversion rate of 1 sell for every 100 clicks. This way you still make some sort of profit. PCC is not only tricky, but it's a numbers game too. Now the numbers can differ depending on how much profit you make on each sell, and the conversion rate can also be a lot higher. Like I said PPC is a numbers game. So it's important to stick to your budget, and to test new ads and keywords. You would be surprised to know that even the slightest variance in your ad can make a big difference. Well, as I like to say get tricky with it! Or in other words tweak the system until it's working for you. Oh and before you begin to advertise using PPC just remember to ask yourself, who is my target market?