Hey lauren, thanks for the nice post! (Dopplr Offsetr is a project of mine...). You make a good point about your network score, in that as the size of your network increases, the amount of total spent carbon probably will too. On the one hand, this kind of sucks, because the data is too correlated with friend count. On the other hand, I think it makes a generally interesting point regarding "winning" a social network arms race. I think that now I have some of this data, I'll add a simple scoreboard to the list: top average or median carbon score.