[gorkemcetin]

I'm personally fond of push notifications. Notifications provide quite a high spike when used timely and in a contextual manner.

[mwidarto]

Although I am agree with this, however soo many developer are abusing this to the point where I think it is ridicilous. Soo many app now give you push notification when the app has not been used for a while and I think that's just as bad as spamming.

[sylvainww]

Agreed. Pretty powerful when used well. Some apps clearly misuse them, though.