Consider the promotions you have running for your site. Did an ad campaign end, causing a drop in traffic? Has a popular site linked to you, causing a spike in page impressions?
A drop in CTR can be caused by a user interface (UI) that's not optimized or by poor targeting. Readers won't click on ads they don't see or find irrelevant. To improve the relevance of your ads, you might want to try section targeting.
If you've implemented or changed your ad server, check that there are no new targeting problems.
サーバーを変更した場合などは、コンテンツマッチに問題が起こっていないかチェックして下さい。
Have you changed the look and feel of your site? Follow our optimization best practices whenever launching a site redesign. An easy way to start is to match the ad colors to the design of your site and choose a top performing unit such as the 300x250 medium rectangle.
CPCs are determined by advertiser bids and are not directly under publisher control. Most large CPC changes are seasonal. For example, certain ad verticals attract more spending during the holiday or back-to-school seasons.
You can always improve your CPCs by choosing ad formats that support all ad types: text, image, video, flash, and gadget ads. More competition means higher advertiser bids.
If overall targeted revenue is changing, determine what your average placement-targeted revenue has been for the past few months. Your goal is to determine if the changes in your recent earnings are part of a trend or a short-term earnings fluctuation.
Publishers can experience spikes in placement-targeted revenue when advertisers run limited-time campaigns. For example, an advertiser may run a large placement-targeted campaign only during the opening week of a summer blockbuster movie.
If you want to increase placement targeting over the long term, set up ad placements. This will make it easier for advertisers to find and target your site.
Many AdSense publishers run multiple websites or have site sections that perform very differently. For example, the article section of a cell phone review site may have a higher eCPM than the forums. Whenever you notice revenue changes at the account level, always determine which of your sites or sections is causing the change. You can set up URL and custom channels to track all the important parts of your account separately. Knowing exactly what is changing and where will allow you to make the smartest decisions about what to do.
Take a broader view and look for historical fluctuations in the metrics described above. Over the same time period last month or last year, you may find similar volatility in your eCPM, revenue, or page impressions.
For example, you can compare the Mother's Day performance of a flowers and gifts site for 2006 and 2007. Is your current account performance consistent with the previous time range? If so, the revenue change you're investigating might reflect a recurring pattern.