A: Well, did you trust Google’s Traffic Estimator when you set up the campaign? Big no-no. It says that you will be in third position from the top on such–and–such a price, when you’ll actually be back on page 3. Set your bids small at first, and check back after your ads have run to see what average positions your keywords have been in. Then go back and adjust them with this new information.
Then, check what countries you are showing in. Your ads may be in first position in England but position 20 in the United States; and Google tells you that your average position is 3 or 4.
Then, click the “search” button again, multiple times, to make sure. Ok, now double check the daily budget for the campaign which you’re in. It could be possible that you have already hit the limit for the day and Google is done showing your ads?
Finally, understand that only a tiny percentage of advertisers in any market show up all the time, 100%, for all searches on a particular keyword. Those are the advertisers that get the most clicks and have the best quality score, and have been in the game the longest.
Q: How do I know upfront what it will cost me to be in various positions on the page?

A: Here are three sites which you can use. They are often inaccurate, but not more than Google’s Traffic Estimator:
www.SpyFu.com
www.KeyCompete.com
www.iSpionage.com
Q: What Is Quality Score, and how is it determined?

A: Google will never openly share the exact formula that they use to determine your Quality Score and your minimum bid price. But here is what we’ve found to matter the most:
Your freekeywords.com wordtracker.com.