The Monday Metric: SEM - Avg. Position is Dead - Long Live Top Impression Share?

Friggin' Google. They took away one of our favorite metrics: "Avg Position." It's now been replaced with "Top Impression Share" and "Absolute Top Impression Share." Why the heck Google? Should we be paying attention to these two metrics? Or are they simply a fun party trick to freak out your vendor of choice with? Find out in this version of the Monday Metric.