Ok, so at the risk of starting another spark plug discussion, I just wanted to post something that some may already be aware of, but I found very helpful.
NGK Iridium Plugs at Advanced Auto Parts (#7803) come with a 3 year replacement if defective. This was great for me because I noticed one of my brand new plugs was cracked (completely my fault as I remember the socket slipping off the plug when I installed it
) so I brought it back to the store.
With the original receipt they replaced it no questions asked.
Although I don't really think $7 is a lot of money, every dollar helps and not having to buy a new plug that I was responsible for breaking is a nice bonus.
Besides, i guess if someone wanted to be dishonest they could get new plugs every year with nothing more than a couple of taps with the back end of a socket wrench, but I am sure nobody would resort to this tactic.