This is a very good point, one I haven't seen made before here.
The "rotten borough" system persisted in England until the mid-1800's, when it was finally reformed. Until then, parliamentary seats based on medieval population patterns and having few contemporary constituents served as safe seats and political spoils. Control of them allowed moneyed interests to control Parliament.
Lot's of people forget that the Boston Tea Party was a protest against a plan, implemented by Parliament, to give the East India Company a monopoly on the tea trade.