advertisements in the notification bar

Most likely it is coming from a third party app that you downloaded. Try uninstalling any apps that you loaded around the same time the Ads started popping up.

 

You can also download an app called air push detector or something similar to tell you what apps are installed that cause this.

 

I had this problem and found out it was coming from an app called "MP3 Music download".

 

It started for me after I downloaded/applied a Yahoo mail app update. I only seem to notice it when I have the mail app open.

 

I have now removed the yahoo mail app and installed K9 mail.

Now no more adds.

 

I got this trustgo security and It found the app that was giving me the advertisements. It works really good and doesn't spam me with random junk.
https://play.google.com/store/apps/details?id=com.trustgo.security

 

I had the same problem and thanks to this post I found and installed Addons detector and found within seconds which app was messing with me, and also a lot of other useful information. Awesome app!

 

unistalling apps still gives you unwanted adds. go to google playor google store, in the menu options tap on "my apps", then "all" and remove all the unistalled apps or remove all the unwanted or unused apps. this should work