Inability to measure the impact of their efforts has been marketers’ number one lament since pretty much forever. Google has announced a free service that will provide some answers – at least within the world visible to Google. Google Attribution (yes, that’s the name) will tie together impressions across AdWords, Google Analytics, and DoubleClick Search, providing a cross-device and cross-channel view, and link them to conversions. Machine learning will figure out the relative contribution of different impressions, finally letting marketers move beyond over-simplified first- and last-click approaches. Some people are skeptical about letting Google measure the impact of ads placed on Google. Others might point out that even Google doesn’t capture all advertising interactions. The service is currently in beta but should roll out soon.