Russian OpenTTD developer have made a complete new economic model. You by stuff at factories and sell it to other factories. Thus you are rather a broker than a transport company, although this is probably interesting too.
More to read here: http://www.tt-forums.net/viewtopic.php?f=33&t=41534
Very interesting...
I've long wished for some Railroad Tycoon II features in Simutrans... :D