- Change history, last 7 days. A loosened match type, a raised target, a new campaign competing internally.
- Your own campaigns bidding against each other. Overlapping keywords or product sets in two campaigns means you pay for the privilege.
- Auction insights. A new competitor at volume moves CPC for everyone.
- Seasonality. Compare against the same week last year, not last month.
- Quality signals. A landing page that got slower, or an ad that drifted from the search, raises what you pay for the same position.
Note that rising CPC is not automatically bad — judge it on CPA. A dearer click that converts twice as often is cheaper per order.