How to track humans, but not spiders?
- by johnnietheblack
I am writing a nice little PHP/MySQL/JS ad system for my site - charging by impression. Therefore, my clients would like to be sure that they aren't paying for impressions caused by robots / spiders / etc.
Is there a decently effective way to decipher between human and robot, without doing something obstructive like a captcha, or requesting "no index" or something?
Basically, is there some sort of "name tag" that legit spiders have on so that my site knows their presence, therefore letting me react accordingly?
And, if there isn't...how do ad companies like Google defend against this?