Valve has released another TV spot for Left 4 Dead, a new clip that will begin airing tomorrow to coincide with the retail availability of the multiplayer zombie shooter. The clip is part of their $10 million ad campaign for the game, though I'm pretty sure they are not sending any of us any of that money for watching it on our own machines. If you're okay with that, you can grab the clip from FileFront and Gamer's Hell. In the meantime, today is the last day the playable demo will be running, and also the last day the Steam Left 4 Dead pre-purchase discount is in effect.