How much can you expect to earn by running Google Ads on your site?

The pay-off per click varies widely depending on what each advertiser decides to offer, based on the profitability of their products and their expected conversion rate (percentage of clicks that deliver a sale). Google is not saying what the average pay-off is nor how does it share the revenue per click with their AdSense partners, but how much you will earn per click will really depends on the topic and the product being advertised. Products with profit margins of $3.00 for the advertiser will probably give you a smaller pay-off per click than a product with a $300 profit margin. Similarly, ads with high conversion rates will normally give you higher payouts than less effective ads, since they can afford to pay more dollars per click, with a portion of that money going to you.

So, just for the sake of giving an example, lets say that your site receives 1,000 page views per day. At a 1.0% click-through rate and $0.50 pay-off per click to you, in a 30-day month you can expect to make:

1,000 x 30 x 1.0% x $0.50 = $150

The more traffic your site has, the more clicks (and the larger the pay-off) you will get.