If you notice a drop in RPM, this could be due to a number of reasons. This usually indicates either a shift in traffic quality, or that our advertisers have reduced their campaign bids on one or more of your domain name keywords.
Keyword settings can be manually optimized using the Master Keywords and Related Search Terms settings via the Manage Domains page.
Please note that RPM levels may fluctuate monthly, seasonally, etc., but revenue should stabilize over time.