I'm in a paid league at Yahoo and we get the add-ons with our FBB Plus. Buzz index and keys to success are worthless. Buzz index tells you which marginal player had a good week last week and is being picked up and which player that everyone picked up last week cooled off and is being dumped. Keys to success is percent of players owned by the best teams in al Yahoo leagues. No rhyme or reason at all to who is on that list.
Research good pickups, analyze your team and see where you need help. Look at other teams in your league for trade opps. This will help much more than any of the silly Yahoo tools.
I think there is a definite pattern to the keys to success list, at least in the long run: you'll wind up seeing lots of players who were undervalued going into this year's draft. Of course, while that's an interesting list to examine, it won't really help you make any moves...
Yahoo has successfully taken everything out of the game that could help you in any way. There is now more "Buzz index", no more "keys to success" and no more "who's hot list". If you want those add ons you need to pay for them.