Dive Brief: 

• Gmail is now placing an "unsubscribe" button at the top of all emails -- creating a highly visible, one-click process to halt unwanted emails. 
• The option had been spotted on many newsletters ending up in the Promotions tab, but is now expanding into Social and Forum tabs. 
• Industry experts are expecting email marketing lists to shrink because of the move.

Dive Insight: 

While its true that email marketing lists will probably shrink because of Google's decision, it's not certain whether that is entirely a negative thing. On the surface, many marketers may panic that their emails will be going to a much smaller group of people, but there could be a silver lining, as the subscribers that don't unsubscribe will be a more valuable group. But time will only tell how much Google's change will hurt or help email marketers.