Is there any opportunity to expand leaderboards to non-member to get a truer sense of ratios? When on the PS3, I belonged to PSNProfiles.com, I believe they had some mechanism that scanned your friends list to look for non-members and add them to the leaderboard (without standard updates that members enjoy... maybe they are scanned once every week). We also signed in with our PSN accounts so it was possible, which is materially different from TA.
On a similar note, are there any talks in the works with the Xbox team to share more data with you to get a better picture of the achievement landscape? You seem like a perfect partner to do the true rarity scores, leaderboards, etc.
One other question, or more a comment really, is that I think TA would benefit largely from people being able to make their own contests and I would also like to see a badge system related to games (i.e Fshguys Badge Calculator on 360voice, GTN's Badge System, even the manual process on Achievement Hounds). Any plans to introduce this in the future?