Google Maps has had ads for quite some time, (AFAIK) all that's new here is option to use custom logos instead of the old purple pin: https://support.google.com/adwords/answer/3246303?hl=en
Disclaimer: Used to work on Google Maps, but I don't anymore, and I know no more about this launch than what the blog post says.
It sounds like leadership is out of ideas if their only ones are to increase the size and frequency of ads on existing apps. That's a bit sad considering the talent they have there.
Ads have always been Google's major source of revenue. Now, their to answer to dwindling revenue is to add larger ads to existing apps [1]
Bigger and more ads is not very innovative for a tech company.
[1] http://www.wsj.com/articles/google-to-increase-size-frequenc...