This is a very interesting article. I once tried to do something like this with an earlier version of SQL Server with the web service API and .NET but was disappointed by the program's reliability. I got the sense that I was trying to do something that the product wasn't supposed to do. I like the fact that your solution appears to be running a stored procedure instead of the .NET API. However, I again wonder if it's still trying to do something that the product creators didn't intend.

Specifically, I have two concerns:

1. it seems like every subscription event that is added would need to be deleted as well or else you'd have lots of unneeded subscriptions on hand.

2. I wonder how robust and scalable the add subscription/remove subscription stored procedures are. What happens if two or more applications are trying to add or remove a subscription at the same time? Has that ever been tested by the product team? It seems like it's something that could break. I would want a lot of error handling around this solution.