Why do TV shows have to go on breaks?

I recently had a conversation with someone about what TV shows I follow, and I complained about Doctor Who being on a break, and there only being 2 more episodes of this series of Downton Abbey left (why, oh why do they only have 8 episodes a season??). The person I was talking to jokingly said "What will you do with your life?", but it's true! Having spent weeks waiting for the next episode of a favourite TV show, it feels really empty when it ends or goes on a break for several months, and I often wonder what on earth I'm going to do with myself. Obviously, this doesn't last for very long, but it always happens.

Well, at least I still have the Big Bang Theory and Grey's Anatomy to look forward to - although, I can't see what on earth those Americans are up to, taking a break every third week. There's nothing more annoying than waking up in the morning, looking forward to a brand-new episode of a favourite show (because, you know, I only get them the morning after... shhh...) only to find that, yet again, there's an inexplicable break in the show.

But Downton ending is really going to make my Monday mornings more difficult, since that's the only reason I've managed to get up at 7 or 8am on Mondays...

1st World Problems much?