From my personal (not very broad) experience and from talking to people who ran/developed free websites with accounts, a typical ratio of total accounts vs acti

From my personal (not very broad) experience and from talking to people who ran/developed free websites with accounts, a typical ratio of total accounts vs active accounts is 10:1, perhaps 10:3 if you are really good. On top of that (depends on the service) you may have a significant percentage of active accounts that represent the same user, but 10% of active accounts seems like a safe bet. TB uploaded/downloaded numbers are really useless, they just thrown them in to look more impressive I suppose. This means they probably have 20-40K of real active BaseCamp users.