Agreed, the differences between municipalities makes this really hard to scale. If data providers like the ones you mention don't exist, the two ideas that immediately come to mind are a) becoming that data provider (obviously), or b) building a platform for municipalities to store their land ownership data on.

Both sound like interesting problems, and it would be awesome if municipal-level land data was available at scale.

Exactly —- while the alert system is interesting and does have value, if they are putting in the tough, long, and grindingly harsh effort to compile these disparate data sources, that itself is the moat and becomes the product. Definitely worth doing!

How do you become that data provider? You need some scalable way to get all that data, right?

I'm not sure how to do it scalably, other than by becoming the host for that data, which is why I included my second option. It seems much easier (and much more profitable) than figuring out how to access the data in its existing format.

Ultimately someone has to do the hard to scale 'last mile' dirty work I suppose.