On the surface, this looks like a very interesting idea. Their implementation got us thinking, however. We've been behind the 8-ball with deadlines and customer requirements for about 60 days now and the maintenance of the website has suffered in the interim. It's made us very aware of the incredible volume of changes to links since we haven't been keeping up with them. Their reply included a range of insult that left us stunned.
Technology is easy, business and sound marketing practices are a lot harder.
If you send automated notices, carefully check and recheck the language for any hints of insult. Treat them as precious resources. Make the decision to change URLs on your website very carefully. The change will cost you in traffic. There are simple workarounds that allow you to keep the benefit of existing links.