Ad Content Checklist

1. Can you locate your ad? Search at least three times or wait a few hours and search again. Sometimes there is a delay between the time you submit an ad and the time it is displayed. Be sure and check the second, third, or even fourth page of results as your ad may not appear on the first page. Also, try the Ad Preview Tool.
2. Does your search return any organic search results? If a keyword does not trigger any organic search results, then paid results will not be displayed. 
3. Is your account active? While you may have given us your credit card information, it’s always good to double check. The Accounts & Billing tab shows the status of your accounts. 
4. Is your campaign active? Campaigns that are live have a status of "active" on the Select a Campaign page. 
5. Is your ad group active? Ad groups that are live have a status of "active" on the Select an Ad Group page.
6. Are your ads and keywords active? The Ads tab and Keywords tab show the status for ads and keywords, respectively. Ads and keywords that are "active" are approved and live. Ads with "inactive" status are live while undergoing review.
7. Does your ad campaign still have budget? Review the Select an Ad Group page to see how much budget you have available or if an ad group is paused because you reached your budget limit.
8. Does your ad group have targeting settings? Are you geo-targeting? If your ad group is targeted to specific locations, times of day, or other targeting settings, you might not be able to see your ad if you don’t meet the targeting criteria. For example, you might be in a different city than the one you’re targeting.
9. Are you searching using the same keywords and match types that you defined for the ad? Make sure your search on www.bing.com or www.yahoo.com takes into account your keyword match types: broad match, phrase match, exact match, and negative keywords.
10. Are you searching using the same language and market settings as your ad? For example, if your ad group’s language and market setting is English—United States and you are searching with English—United Kingdom language settings, you will not see your ads.
11. Are your bids competitive enough for the ad auction? As new advertisers from Yahoo! Search begin to compete in the Microsoft adCenter auction, bid prices could be affected by more advertisers bidding on the same keywords. Monitor how your bid prices affect your ad position, increase your bids, and set incremental bids as needed to help meet your ROI goals. It is important for you to bid an amount with which you are comfortable and makes sense for your business. 

You may also want to consult adCenter Help: US | UK |  FR | CA (English) | CA (French)

If you still don’t see your ad, then it’s time to contact your service representative.