Not only is it important to microchip your pets, but also to keep your address updated with the company:
http://www.kvoa.com/news/stephen-a-beagle-from-japan-turns-up-in-tucson/?fullsite

Collars and tags can come off, or worse, strangle your pets if their collar gets caught on something and isn't loose enough to slip over their heads.

I have my Goldendoodle microchipped. I agree it's a good idea.

microchip and keep the agency informed of your changes in addresses. It's an expense, but well worth it, especially if you are just adopting or buying a pet. Most vets today have a reader to view for chips and the information on them- any strays brought in by caring others are scanned. Unfortunately, here we have a huge coyote problem, and from seeing all the lost pet signs (usually of the smaller varieties, dog and cat alike) it is a sad time for those pet owners. It's a small expense in the long run, if your beloved pet gets out and galavants around...a chip, a lot of prayer, good vets, good people, good signs and ads posted- you will get your friend back very quickly. There is such pain in a lost pet situation. I believe in chips, fences, good vets and good neighbors- and just keeping your eyes and ears open for that opportune moment when your friend may decide to go exploring. Don't even get me started on the people that steal pets, and yes, it does happen.

The use of the microchip in this manner is a true technology advance.