Ask HN: Customized HN activity feeds to your mailbox?

Mostly out of curiosity while I am reading up on the lean methodology, I am in the process of building a system that scans HN and can generate custom reports including:

- Full Daily activity: top 100 posts, and their stats

- Customized Daily Activity: like the above with customized with custom keywords per user.

- Top X: Most popular topics per hour/day/week/month

- Comment Tracking: Track comments to your posts, within a certain time frame of first posting

- User Tracking: track and report on the activity of users that you follow

- Something else that you may find useful?

- etc.

If this becomes relaity, the service may expand to other websites in order to offer similar functionality.

My question is:

Would you pay for this service? If so, how much would pay monthly/annually?