**eCPA – effective cost per action**. We add an action count (Lead for instance) to the previous examples, and calculate how much did the advertiser actually paid for each Lead act. **Lets assume the advertiser is profitable when he pays 5$ per lead. **

**eCPA on a CPL/CPA/CPS model**

Here naturally, the eCPA is the predefined CPL.

Day 1 | Day 2 | Day 3 | |

Impressions | 200,000 | 150,000 | 200,000 |

CPL [fixed rate] | $5 | $5 | $5 |

Leads | 10 | 15 | 12 |

Cost | $50 | $75 | $60 |

eCPM | $0.4 | $0.5 | $0.3 |

eCPA [fixed rate] | $5 | $5 | $5 |

Although the cost per Lead was as desired by the advertiser, the publisher might drop the campaign receiving only $0.3 eCPM on day 3.

**eCPA on a CPM Model**

In this case, the eCPA reflects the total cost each day divided by the number of leads.

We can see that the advertiser has very little control regarding the price he pays for each lead.

Day 1 | Day 2 | Day 3 | |

Impressions | 200,000 | 150,000 | 200,000 |

CPM [fixed rate] | $0.5 | $0.5 | $0.5 |

Cost | $100 | $75 | $100 |

Leads | 10 | 15 | 12 |

eCPM [fixed rate] | $0.5 | $0.5 | $0.5 |

eCPA | 100/10 = $10 | 75/15 = $5 | 100/12 = $8.3 |

Here, the publisher might be satisfied with his 0.5$ CPM but the advertiser loses on day 1 and day 3 paying more than 5$ per lead dropping the campaign as well.

**eCPA on a CPC Model**

Similar to the CPM model, the eCPA reflects the total cost each day divided by the number of leads. Although sometimes there is some correlation between the number of clicks and the number of acquisitions, still the advertiser has little control over the price he pays for each lead.

Day 1 | Day 2 | Day 3 | |

Impressions | 200,000 | 150,000 | 150,000 |

Clicks | 1000 | 1500 | 1000 |

CPC[fixed rate] | $0.08 | $0.08 | $0.08 |

Cost | $80 | $120 | $80 |

eCPM | $0.4 | $0.8 | $0.53 |

Leads | 10 | 15 | 12 |

eCPA | 80/10 = $8 | 120/15 = $8 | 80/12 = $6.6 |

Although the publisher in this example receives satisfactory eCPMs, the advertiser is not profitable at $8 per lead.