EPC – Earning per Click
The acronym EPC stands for average earnings per 100 clicks. EPC is the ultimate test to tell how well an affiliate merchant campaign is performing. Just because a campaign pays a high commission doesn’t mean it is a preferred program. A campaign with a lower-paying commission but a higher EPC will actually be more appealing to affiliates. This is because the affiliate will earn money on average for each click they can generate even at a lower commission rate.
EPM – Earnings per Thousand
The acronym EPM stands for average earnings per 1,000 impressions. An impression is each single instance that the ad is viewed. The acronym is derived from the fact that “M” is the Roman numeral for 1,000. Affiliate networks use both EPC and EPM in publisher performance reports.