Just like iPod’s debut, when Microsoft introduced Zune, third-party companies also provided extra oomph for the media player. However, it’s a testimony to iPod’s sales numbers that supplying third-party add-ons has almost become an industry onto itself, with companies competing against one another hoping to grab some of that after-sale iPod market.

And third-party Zune devices? They’re there. But you might have to look for them.

But have no fear, Microsoft is willing to help. The company recently issued press announcing several new Zune add-ons.

Like the $99.99 Zune Home AV pack connects a Zune to your home audio system and comes with a remote-control.

Or the Belkin Sport Armband, which lets you wear your Zune on your arm just like all those people you see at the gym wearing iPods on their arms.

Then there’s the Altec Lansing iM414 speaker dock for Zune, a-self contained unit that enables Zune owners to blast their friends with their Zune tunes.

All in all, Microsoft announced 23 licensed Zune partners, including GPX, Griffin Technology, Monster Cable Products Inc., and Memorex Electronics, with most of the companies providing Zune add-ons similar to the iPod extras that have been available for the past six years.

But the fact that Microsoft has to promote its Zune partners is the latest example that its personal player isn’t exactly the big seller many predicted it would be over one year ago.

Microsoft’s third-player Zune press release pretty much slid through the cracks of mainstream media. Not exactly a good sign for what was described as an “iPod killer’ in the weeks leading up to its launch one year ago.