Yes, it is a anti spam measure. It is a simple alerter to us MODs that a newbie posted. So we look, and see it isn't a spammer and approve it. It does newbies first posts and then newbies first links they put up.
In this way, even a bored spammer that sits here posting up car questions only to come back later and post spam, gets caught. YEP! They try it all the time.
Welcome aboard! LOL