Filtering through information overload

I spend on average 3 hours a week on hackernews because it's the best place to find emerging trends and stay up to date.

I thought about building an app that sends you trend alerts when something you're interested in reaches the top page on HN. It wouldn't spam you with every single other post. (and I'm just 3 days away from having a 1st prototype)

Would you buy such a service or do you just love the experience of browsing HN in itself so much that you don't want need such a tool?