Exactly. To Google, wanting to use a domain other than Gmail is a strong signal that they can probably shake you down for a few bucks a month. Sure it’s just $7 for most of these people and they probably only have 1-2 accounts. But multiplied by how many million people they saw using this feature it could be worth it to Google. Plus also ending the infra cost of fetching.

For those of us who were just using the feature to aggregate mail from other email addresses like an old Yahoo account or something, I doubt Google cares about it, they even probably kind of liked it that you’re viewing their ads instead of the other guys, but they probably don’t matter enough.