Horoscope Zone started as a potential way to manage an email list that was getting daily emails, that would be a high delivery, low complaint list. We were managing lists for people, but most of it wasn't targeted, and had high complaint rates.
Horoscope Zone had a pretty solid methodology, and a good technology stack to build on.
It did not have enough momentum to really make a business out of it. The idea was that it would get subscribers alot faster than it did, and we'd be able to monetize them a lot better than we did.
It crapped out because it was growing too slowly and we got caught up on other things.
If I had to do it again, I would probably either find a way to scale up the subscribers quicker, or find a way to keep my costs a lot lower. Or both :)