I have a website and I'd like people to be able to subscribe to be notified by email when there are new comments on a page.

I need the subscriber to be able to unsubscribe with 1 click, no login required.

I am thinking the best way to accomplish this is to include in the email a URL with a unique id for that specific subscription., such as example.com/unsubscribe.asp?id=B1B8FC7A-809C-4A1C-B44B-F8058235C4DB

My question is what is the best way to accomplish this.
I am thinking of using the uniqueidentifier datatype and RowGuid
[subscribe_guid] [uniqueidentifier] ROWGUIDCOL

Is this a functional method, any suggestions or alternatives? Also what is the difference between uniqueidentifier datatype with ROWGUIDCOL and without?