Intro songs - why do bands/artists feel the need to do this?

So driving around tonight, the new Saliva song comes on the radio. It sounds alright, music-wise, but I had to make my own interpretation of it.

Why?

It's one of those songs, similar to the first single of their last CD - "Ladies and Gentlemen" - where they feel the need to introduce themselves to their audience.

Why do artists feel the need to write a song "Hey we're back again, in your stereo! We got a great new sound (which sounds like all our other songs) and we're gonna rock your socks off! YEAH! WOOOO! We're back, get ready for it!"

1) Obviously "you're back" if you have a new song with a new album and they're playing it on the radio... and obviously I'm aware of this if I'm listening to you or I bought your CD.

2) Okay, so you're new is album going to rock and felt the need to include this in your introductive first track/single - if I'm already listening to the CD, I think I'll be able to figure that out with having an intro tell me that and if I'm listening to the radio, I'm not going to know until the album hits stores and I can go out and get it, so basically your song is just an advertisement to me at this point.

3) Why do some artists have the need to put this stupid 'introduction' song on their album and then make it a single? It's a waste of a track! Don't tell me your new album rocks, show me! Singing a song about how you're back with a new album doesn't really help me when I'm either already listening to it or this lone song is on the radio.

4) Why are you talking specifically to your fanbase? Your fanbase isn't the ones that care - they bought the album already. Granted when it's on the radio it may introduce you as an established band with a rockin' new album to those that haven't heard your previous songs, but still - doesn't mean you have to torture the rest of us with stupid intro songs like this!

Am the only one that thinks songs like these are stupid and pointless? I mean most the times, bands/artists have a ton of material they recorded but when it comes time to put it on an album, they have to narrow it down to about 13 tracks, so why are they wasting one on an intro song? Was there really no better songs they recorded that they could have picked for the 13?

I don't get it... and this is at least the 2nd album in a row where Saliva has done this - the first single of the new album is the first track off the album and all it does is reintroduce them to their fanbase and they sing about how great the new stuff is. And it's not just Saliva that's done this - other bands and artists have done it too, I just happened to hear them tonight and felt the need to rant about this 'trend.'