I have been receiving monthly checks from Google since 2003. My earnings are usually in the mid 4-figures.
My sites have been around for a long time and I have a great deal of traffic so that's a big reason why I earn 4 digits per month.
AdSense changed their terms and you can no longer show your earnings unless you show the finalized report. But just to be safe (they've been disabling a lot of accounts lately and I don't want to take that chance), I've blurred out my report from November, 2014.
I promote my sites on social media, create YouTube videos, get traffic from Google, etc. Making a lot of money with AdSense is all about numbers. The more traffic you have, the greater the earning potential.
My checks weren't always this large. I think my first month's earnings in 2003 totaled less than $20. However, as my traffic increased, so did my checks.
You should also DIVERSIFY your income and earn money in other ways like I do with affiliate marketing, etc. Why? Because AdSense income is not stable. It fluctuates greatly from month to month.