The time you get alerts each day is the same?Or when you browse some websites you will get it? Get Droid Wall will be helpful. Or you can have a Dolphin License to have the ads locked.
I'm not sure if it happens at the same time every day. I'll be sure to make note of that.
It's not when I'm browsing a website. It comes when the phone is in my pocket, screen off, not being used. It's definitely an alert (as opposed to a text). It has a red star icon in the notification pulldown tray. Next time I get one I'll post details/contents.