where is the bitcoin mostly used after speculation on the markets?
what is the area of economics that don't work without bitcoin ?
The first Satoshie's statement on where Bitcoin can be used has been sounded on this forum:
Bitcoin would be convenient for people who don't have a credit card or don't want to use the cards they have, either don't want the spouse to see it on the bill or don't trust giving their number to "porn guys", or afraid of recurring billing.
Probably he was correct and one of the widely usages of bitcoin is the stashing money from prying eyes of spouse. Correct me if I'm wrong and there are the older messages from him on this matter.