One of my sites is struggling compared to the rest, so I decided to try Adwords. Its been many years since I used them, and in the past I had success with them.
I have my campaign set for a USA audience only, the site isn't relevant to anyone outside of the USA. Here is the result of the first day (so far):
41 clicks recorded by Google. Of these clicks:
3 from Iran
4 from a DigitalOcean server farm
3 from South Africa
1 from OVH server farm in France
2 from Google's company IPs
2 from Giglinx server farm
1 from linode server farm
1 from Midphase server farm
So out of 41 clicks, almost half (17) are not human and/or from outside the area I specified. It appears click fraud has become widespread. I can't help but think Google overlooks it, because it only took a minimum of effort for me to determine via headers these visits were not valid. In the past there was occasional click fraud, but I never saw anything this bad. I've contacted them concerning this, and will see how it pans out.