Here is our current curation of the official Google documentation on AdWords Call Metrics.
The initial Inside AdWords blog post.
Measure the phone calls you get from AdWords
The real nitty-gritty AdWords Help articles.
About AdWords Call Metrics.
Sharing Call Extensions Across Multiple Campaigns.
Campaign Segment Data and Call Extension Data.
The pivotal breadcrumb.
Another intro from Google Ad Innovations
The intro video is included in other documentation, but here it is on YouTube.
More AdWords Call Metrics information.
Our curation of AdWords Call Metrics Resources – Articles, Case Studies, Best Practices – suggestions welcome
Our original post on AdWords Call Metrics.
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