Been reading this post and finally decided to give my opinion. I know, I know who cares, but we've been going to WDW forever and have seen MANY changes over the years. Personally I don't care if people wear the buttons 6 months after their birthday. I think it is a fun thing to do. The only thing is....YES the cast members are so used to buttons that it is not special anymore. Years ago it was. I can remember when my kids were little (they are adults now). We always were at WDW during my son's birthday and he would wear a pin and get tons of pixie dust. Desserts, getting to ride a ride again, cards, characters would write Happy Birthday in his book, etc. etc. Now SOOO many people are wearing buttons that CMS have become numb to them. I'm not saying it's a bad thing, yes some CMS still wish you a Happy Birthday, it's just not the same. Now, with that being said, I find that big Anniversarys still do get attention. We were there this year during our 40th Anniversary and got loads of attention. A lot of CMS, and for that matter strangers, kept asking us what the secret is. My favorite was the CM at Epcot who asked me if I married at age 10!
ANYWAY, what I am trying to say is yes go ahead and wear a pin for birthdays, anniversarys, anything you want, just don't expect anything and it you get something just enjoy it!!
Enjoy The Magic!!
And BTW, the "secret" is laughter and lots of trips to Disney!! LOL!!