# Basics

**CPC:** Cost Per Click - online advertising model where advertisers only pay when a user actually clicks on an ad to visit the advertiser’s website.

Ad4Game can run ads on CPC basis and advertisers are not charged for multiple clicks on the same banner by the same visitor in 24 hours.

**CPM:** Cost Per Thousand Impressions - online advertising model where advertisers pay for each thousand ad views / impressions of their advertisement.

CPM statistics are provided to analyse campaigns.

**eCPM:** Effective cost per thousand impressions - The cost of a campaign divided by the total number of impressions delivered by that campaign, multiplied by 1000.

Average CPM statistics are provided to analyse campaigns.

**CPA:** Cost Per Action - online advertising model where advertisers pay for each action (for example player signup or game client download) resulting from their advertisement.

Detailed CPA statistics are provided for the advertisers who use the tracking codes.

**CTR:** Click Through Ratio - the percentage of ad views/impressions that lead to a click.