AdWords Traffic Estimator Inaccuracies

I mentioned in a previous post that AdWords can give you misleading estimates of both available traffic and CPC pricing. Before initializing a campaign I used the Google AdWords traffic estimate tool. The following is a partial screenshot of it's estimation.

As show, given a CPC rate of $0.12 and a daily budget of $10.00, I would receive all the clicks I requested. Satisfied, I created a new AdWords campaign and inputed the exact same parameters (both were targeted to the US alone). To my surprise the results were very different.

Okay, wait...0 predicted clicks? At the top of the page there was an explanation for the discrepancy.

The fact that I had never had a campaign meant my estimates would be rough. Makes sense but wouldn't account for 0 clicks. The next bullet point did. Only Google's search result ads are included in the in-campaign estimator. I assumed Google would deliver ads as predicted by the traffic estimator tool but since it was in the campaign, they didn't indicate estimates of the content network.

Unfortunately, only a few clicks ever came through. I emailed Google but their response was vague. If it was another company I would suggest it was a form of baiting. On the other hand, I wouldn't accuse Google of poor programming.

The deviation is greater when you target a geographically expensive area (e.g. New York City). From the looks of it, they are using the system-wide average instead of geographic average resulting in a gross underestimation of cost.