I just wanted to post this PSA because this seems to be a growing problem (and one that I've run into for the second time, now).

There is a 'new' push by developers offering 'free' versions of apps towards having ads pushed to the notification area of our Android devices. I don't have a problem with this, per se, but it would be nice if (1) the devs engaging in this activity would warn users; (2) this activity was limited to when the apps in question are actually running rather than as long as said apps are installed on a device.

There are a several apps, that you can download from Google Play, that will identify the offending app(s) so that you can uninstall them if you wish. The two apps that seem to be the most popular are:

Air Push Detector

and

Addons Detector

Neither of those apps will delete the culprit app for you. They will only identify the app so that you can make your own decision as to what to do with them (i.e. delete them or just leave them alone, happy that at least you now know where the issue lies).

I don't install apps very often, and when I do it is usually a bunch of apps within a couple of days, testing, then purging of the ones that I don't like. This makes it difficult to figure out which app is the offending one compared to if I would just install an app or two at a time, every now-and-then.

In my case, it first happened about a month ago, to my Asus Transformer. I figured that it had to be linked to an app that I had installed but I couldn't figure out which one it was, even after deleting several apps. I ended up getting frustrated and performing a factory reset and restored apps only as I needed them. Later on I found out about the two apps to which I linked, above.

Just today, it happened for the second time, but this time on my SG Note. I downloaded and ran Addons detector. It turns out that the culprit was an app that I installed and tested yesterday, but wasn't even using. I had downloaded two apps for the same purpose, tried them both out, and settled on App #2. App #1, however, was pushing ads to my notification bar even though it wasn't running. This, to me, is pretty sneaky.

With banner ads, at least they are in-app, meaning you only see them when the app is running. With these notification bar ads they can keep being pushed to your phone even if the app that triggered them isn't being used. Usually once I finish my batch testing I delete all the apps that I'm not using, and purchase paid versions (where they exist) of all of the apps that I have decided to keep. In this case, I downloaded a bunch of apps over the course of the day yesterday and had done pretty well with remembering to erase the ones that I didn't need shortly after testing them out. The culprit app was one of the last two apps that I had downloaded before calling it a day; uninstalling it after deciding on the other app in the pair slipped my mind (I was just glad to be done).

Anyway, my point has already been made, but to repeat: If you start seeing ads pop up in your notification area, it's probably due to 'Air Push' which is associated with many of the 'free' versions of apps present and popping up in Google Play. You can run either of the two apps that I linked, above, to figure out which programs are the culprits.

Hopefully this saves someone a bit of grief.