Cost Per Mile (CPM)

Also known as: Cost Per Mile, Cost Per Thousand, CPT

CPM is what you pay to send 1,000 emails through a provider. It shows your cost per thousand sends so you can compare pricing between tools.

Cost per mile or CPM is a simple way to price email sends. Instead of charging for how many contacts you store, it focuses on how many emails you actually send. You pay a set amount for every block of 1,000 emails. This makes the math simple when you plan campaigns.

CPM matters because it ties your spend directly to sending volume. If you keep your list clean and only email engaged people, your costs stay under control. It also makes it easier to test new campaigns since you know roughly what each extra thousand sends will cost. This helps you judge whether a campaign is worth sending.

You can estimate cost with a quick formula. Take your total emails to send, divide by 1,000, then multiply by the CPM rate. For example, 25,000 emails at a $4 CPM will cost about $100. Running this check before you hit send keeps budgets realistic.