Facebook's redesign at the end of September was accompanied by a major, and not universally loved, change: sharing of things you listen to with Facebook-connected apps now happens automatically instead of only when you choose it. The negative user feedback has led Spotify to offer a private listening option, but overall, the impact for the music services that chose to sign on with Facebook has been phenomenally positive. Mog, a US-only free music subscription service, has been among those beneficiaries, with its traffic numbers going from 40,000 active users at the beginning of October to north of 160,000 at the month's end. Company CEO David Hyman keeps it short and sweet in describing Facebook as "the best distribution platform [Mog] have ever had." Of course, as pointed out by All Things D, in spite of this rapid growth, Mog and Rdio and the current leader in terms of users, Spotify, still have a challenge on their hands in converting these non-paying users into loyal purchasers of their paid services. Somebody's got to pay for all that free music, after all.