Just to confirm, official verizon stores only?
No, online also. I went round and round with the CSR's on 611. The first CSR said that it must be instore only.
So I called the nearest store (200 miles away) & they said it was in store, online, and over the phone. They also said that the offer was good until Dec. 31st. I asked if there was some code I could give to the CSR that they could find in their system. She said no but when you go to checkout, the 50% off is automatically applied.
So I called back to *611. This guy knew about it but said it was only for the standard battery. He did confirm that it goes until Dec. 31st.
So I went on Verizon's site. They now have a bunch of accessories on their, including the standard and extended batteries (they didn't as of last night 10pm CST). I added both the standard and extended batteries to my cart and hit checkout and both showed 50% off. I haven't gotten it yet since I'm still deciding if I'm gonna go with a spare standard or an extended battery.
Also, if you buy 3 accessories you get 20% off, and 5 accessories gets you 30% off. I don't know if the 20 & 30% discounts work along with the 50% off of the batteries though.
Right now I'm thinking of going with the car mount from Verizon also. I read the description of the same one (same part #) on HTCPedia and it said there are inserts so it works with either the standard or extended batteries, so that's a plus in my book.