Japan’s #2 Carrier KDDI Pushing Ads On Android Notification Bar
KDDI, Japan's second largest cellphone carrier is being blamed by users on Twitter [J] by displaying advertising on Android "as a system notification".
Here is a sample screenshot informs from KDDI to you "Diet by an App",
on the system notification.
The Android app to insert such ads on the Android system notification is an officially bundled "au one Market", alternative Android Market powered by KDDI au (Google's Android Market also exists on the phones).
According to @jn_mo, this was introduced at the app's update 2 times before. After update, user will be explained 1. au one Market app stays resident even when you are not using the app, 2. notification space will be used to inform good deals to customers.
The agreement screen has a large "OK" button. Just above the button, there is a link saying "Click here if you do not like to see the ads".
As some users pointed out, there is a similar service AirPush from US, which utilizes notification message for ads, which seems not welcomed by every user. This KDDI's one could spread wider as it is by cellphone carrier with pre-installed, unable-to-remove, automatically updated app.
Author Information @akky(Akky AKIMOTO) is one of the first pro-bloggers in Japan [J]. He also leads Asiajin, writes for Japan Times, does consultation for foreign companies interested in entering Japanese web market. 
