How does google determine adsense ad pay ?

Hi there,
I was wondering if anyone has an idea how google calculates how much an ad click will pay. Is it based on a niche? On location? On the type of content?

Find the answer here: https://support.google.com/adsense/answer/32725?hl=en-GB

Cost-per-click (CPC)

The cost-per-click (CPC) is the amount that you earn each time a user clicks on your ad. The CPC for any ad is determined by the advertiser; some advertisers may be willing to pay more per click than others, depending on what they're advertising.

https://encrypted.google.com/search?q=adsense+ppc+cost+of+click

yes, it depends on CPC. and CPC counted based on the user's location ( USA/UK clicks will get you high rates), your blog/site's niche ( adsense shows niche relative ads + interest based ads. if you have technology related blog, users will more likely to see tech related ads in which they are interested . some niche got high rates like health and technology while some has very low rates like dating and friendship) .