A couple of weeks ago I began noticing discrepancies between my Adwords Campaign reports and what i see in my logs. Because my landing page is an article about a specialized topic with low search volume, the page doesn't get much traffic, and so it's easy for me to check log entries for individual visits against the Adwords reports, which can be segmented to within a given hour.
So about two weeks ago i began seeing clicks reported by Adwords during hourly time periods for which my logs showed no human visitors. Since then, I've been seeing 1-3 cases of this almost everyday.
I don't think my server has been down during this time, unless it was for very short periods, certainly not down enough to account for what I've been seeing. So now I'm wondering if these discrepancies are due to fake clicks.
I'm not losing any of my own money, because I started my Adwords account with a $100 coupon, and then got another $50 credit later as incentive for creating a new ad group, and I still haven't spent most of that money. But i still find it a bit annoying to be charged for bogus clicks, if that's what's happening.
So has anyone else ever noticed this kind of discrepancy, and if so, what conclusions did you reach as to the cause?