Use the daily limits and check in every day to see what's going on. This could never happen to us as we know our maximum exposure.
You are very wise, SlyOldDog. When one is advertising at this level, it is especially important to monitor.
Although every advertiser has their own way, I'd like to advise against the fairly common practice of setting a daily budget well beyond that which one is actually comfortable spending.
Many advertisers do this in an effort to guarantee that their ads will show every time. The problem is that when the ad shows, it can be clicked on - and these clicks can quickly amount to more than the advertiser ever really intended to pay. Yet they have set a daily budget that allows it.
When one does this, it is critical to monitor closely to avoid surprises.
Just my $0.02.
If a site using Adsense has optimized for your keywords and got to the top spot you will get plenty of traffic.
This was happening to people advertising on E-Spotting. Some E-Spotting affiliates optimised their sites for Google high volume keywords, and achieved the Google top spot. The people paying for the #1 E-Spotting spot got more than they bargained for. From a few dollars a day to a few hundred.
I've opted out of content matching. Too many "unknowns" for me.
It was also my finding that the content traffic did not yield the ROI that search traffic does.
I have about 30 negative keywords per campaign. The accounts I manage are strictly B2B and I was seeing too much residential/non-business traffic.
And as mentioned above, setting a realistic budget is absolutely imperative.
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