I have a collector membership as a part time dealer too I do find the cac sticker helps sell it much faster. They’re not foolproof. I’ve seen cac stickers on coins I really don’t like. But the majority are better coins and with all the crap that’s in holders during various shifts up and down on grade opinions and leinincy on some issues at times it helps. That being said there’s some very good coins that for whatever reason don’t have a sticker either. I don’t reject these either. I buy the coin first not the holder or the sticker.