MTV and VH1 are part of the MTV Networks owned by Viacom, so even if you boycott the MTV channel, you're still feeding into the machine by watching VH1. So there's no point in saying "MTV is run by money hungry fiends who don't care about real artists so we should boycott them", because VH1 is still owned by those same money hungry fiends and they're still making money off of you and influencing you.
Edit - If you really wish to not support Viacom, it's business practices, what it represents and the multi-media it offers to its consumers then you should also stop watching Comedy Central, Nickelodeon, Noggin, Spike TV, TV Land, etc etc, which are all owned by Viacom. The list goes on and on, Viacom is massive.
So good luck raging against the machine. :roll: