Have your AdSense earnings been in a slump? This could be for for any number of reasons, and Google took to its Inside AdSense blog on Friday to help publishers troubleshoot the problem.

As the company notes, there are many factors that can have an impact on your earnings, but you should start by looking at clickthrough rate (CTR), cost per click (CPC), page revenue per thousand impressions (page RPM), and page views.

All of this information can be found in the Performance reports tab in AdSense.

“When troubleshooting changes in page views, it’s a good idea to extend the date range of your reports out to 30 days or more to help identify trends or specific issues,” writes Google’s Rachel Barrett. “A drop in page views could simply be seasonal; retailers, for instance, tend to see a traffic drop after the holiday season. But a decrease can also be due to a change in your content.”

If page views are the problem, Google suggests promoting your site with other major sites that cover the same topics and through social media (including groups), using Google Search Console to make sure your site is being properly crawled and index, updating your site regularly, and sending an email newsletter.

If your search rankings have dropped, Google offers a Webmaster Troubleshooter to help you address issues.

Regarding CPC, Barrett says, “See if you’re using the best-performing ad sizes. Generally, our most successful sizes for CPC and CTR are 720×90, 336×280, 160×600, and the 320×100 mobile banner. Make sure you’re not blocking ads you don’t need to. Blocks on too many advertisers, ad networks, general or sensitive categories will often decrease CPC because there are fewer advertisers in the auction bidding on your inventory. The more inventory your site has access to, the greater the chance that auction pressure will drive up your CPC. Look at how seasonality can affect your advertisers’ bids. For instance, swimsuit advertisers often increase their bids in the early weeks of summer. But if your site caters only to students, you should expect traffic to fall in the summer.”

As she notes, CTR and page RPM issues could stem from issues with your site design or targeting. She runs down some best practices in the blog post while providing additional resources for addressing the various issues mentioned.

Image via Google