Last week's Gmail for Android update (4.6) included groundwork for in-app advertising for the first time since the app's début. Ads have not yet begun to appear in the app, and there is no activation date as yet, but the code is there, an exegesis of which by Android Police is shown here.
The top third of the code grab above shows you will be able to either save Gmail ads as messages or delete them. In other words, no matter how Gmail ads end up looking or how they will be placed, Google will eventually be encouraging you to interact with the ads the same way you do with letters from your mother. The middle portion above shows there will be a place to store the ads, and the bottom portion will define the ads' visual attributes like borders and headers.
This groundwork represents another step in the decades-long negotiation process between Internet users and advertisers. The Gmail app for Android is used by hundreds of millions of people representing a notable revenue stream, to say the least. Google's challenge is to balance visibility with unobtrusiveness, gradually working ads into the Android experience as users acclimate to them.
The change comes with a variety of other developments in this latest update. Whenever a sent message hasn't quite been sent yet--e.g., in the case of a premature power-down, connectivity drop-off, or glitch--a notification in your Sent folder indicates as such. Faceless silhouette icons for contacts without profile pictures are replaced with the first initial of the first names of those contacts. The cancel button on the confirmation window when sending messages has been removed; use the Back button instead. And finally: All icons on the UI buttons have been darkened a bit.