I can see that it's useful, if somebody's replied to you on a thread that's moved on, and you might have mised it had you not got the email to say youd been tagged.
But what about when somebody takes a dislike to you on a thread and starts tagging you repeatedly like a dog with a bloody bone? Hey presto - inbox clogged up with vacuous crap.
Not a specific TAAT, as it hasn't actually happened to me yet, but I've seen several people pleading "stop tagging me!". So, is it working?