How CPC is calculated
Cost per click is the average price of one ad click:
CPC = ad spend / clicks
A worked example: a Google search campaign spends $1,500 and gets 5,000 clicks. CPC is 1,500 / 5,000 = $0.30.
On search networks you often bid on a CPC basis directly. On social networks you usually pay per impression, so CPC is derived from CPM and click-through rate:
CPC = (CPM / 1,000) / CTR
With a $9 CPM and a 1.5% CTR, each click costs $0.60.
From CPC to cost per install
For an app campaign, a click is only the middle of the journey. The user still has to reach the store, install and open the app. That gives a simple bridge to CPI:
CPI = CPC / click-to-install rate
If CPC is $0.40 and 20% of clicks become installs, CPI is $2.00. If a faster store page or a better deep link lifts click-to-install rate to 30%, CPI drops to about $1.33 with no change to the bid. This is where measurement matters: you need accurate click and install counts from the same source to see which step is leaking.
What affects CPC
- Keyword and audience competition. High-value search terms and audiences attract more bidders.
- Ad relevance. Platforms reward relevant ads with lower prices per click.
- Creative. A clear hook raises CTR, which lowers CPC on impression-priced inventory.
- Click quality. Very cheap clicks can include accidental taps and click spam. A click that never leads to an install is a cost with no value.
Using CPC well
Treat CPC as a step in a chain that ends in revenue. Compare it with click-to-install rate, cost per install and ROAS for the same campaign. Linkrunner records clicks on its links and attributes installs and in-app events back to the campaign, ad set and creative, while spend syncs from Meta, Google and Apple Ads, so cost per install and cost per event sit next to each other in Linkrunner analytics. When click counts look inflated compared to installs, the click flooding and click injection rules in Fraud Control can flag the traffic and withhold postbacks.