App Store badge icon for updates changed?

I used to get a number on the badge icon on the App Store when any apps needed updates, to alert me.

Anyone have any idea why that number will only now appear if I a) go into AppStore and then b) click on update.

Not seen a badge number icon on it for a few weeks and I just clicked on 'update' and got '13' needing updates which then showed on the icon.

Just wondered ...