Ya... U have said it right. Here the main cost is in the advertisement. U need to calculate the cost of having so many users on their sig campaign pushing all their products desperately. In marketing terms, it is called branding cost. In reality, if you conider their services like exchange, mining or cards, they are of inferior quality than their competitors in respective fields. Especially, you should consider twice before ordering cards from an unknown authority registered in Panama.
Bit-X is a trademark of XBIT Ltd.,
a licensed Forex participant.
This link took me to a Belize site, where this parent company's admin email is listed as
admin@x-bit.co. I checked
http://x-bit.co, but it looks like a parked domain. Now I checked
http://x-bit.co/main. It is hotlinking an under construction image from
www.chordindia.org. You want me to believe that this is a legit company ?
This domain was just parked for the moment, it's actually under construction. You can expect something shortly

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As for Bit-X's address:
Registered office: Portland House, Bressenden Place, London, SW1E 5RS, United Kingdom.
© 2014 bit-x
bit-x.com is a trademark of XBIT Ltd.,
a licensed Forex participant