@Peter78

partially your question has been addressed in other replies. The most obvious reason for people to buy LEOcoins at the internal exchange is because they wish to do so.

Those who have access to other exchanges, probably will purchase there where they can get LEOcoin cheap. I also wish to point out that there is also trading being done outside of the internal and external exchanges; direct deals and transactions between two parties, e.g. between merchant and customer or between investor and cryptominer.