Cost per mille

Okay kiddo, so have you ever heard of advertising before? It's when grown-ups want to tell other people about their products or services so they can try them out. One way they do this is by putting ads on websites that lots of people visit.

Now, the website owner can make money from these ads by charging the advertiser for every 1000 times the ad is shown on a web page. This is what we call cost per mille (CPM).

Imagine you have a lemonade stand and you put up a sign that says "Buy my delicious lemonade!" Every time someone walks by, they see your sign. Now, if you had a CPM advertising model, you would charge someone who wants to put their own sign on your stand for every 1000 times their sign is seen by someone who walks by.

So, if you charge $1 per mille, and a billion people walk by your stand and see the advertiser's sign 1000 times, the advertiser would have to pay you $1 billion!

That's basically how CPM works - an advertiser pays a website owner for every 1000 views their ad gets on a web page. The website owner gets some money from the advertiser, and the advertiser gets to tell lots of people about their cool stuff. Cool, huh?