I meant that if your friend’s website is owned by himself/herself, then the changes are already known in the database. It is easier to do a lot of alert either by scheduler, by db table trigger, or other mechanism without consistently checking on this webpage every minute or so with extra web traffic without knowing what exactly the change types are (forum/posts/rely, etc.)
If the website you are monitoring is owned by other people then the 1st option doesn’t really exist.
I am not totally clear. You mean forward the new changes by email? It is a good idea but requires more work.