Demographic vs geographic voting

I'm not a US resident, and I probably know very little of the US political system. But I did spot something on a web site somewhere which made the electoral college system seem a lot more sensible.

Democracy is the tyranny of the majority; the problem is that that majority isn't evenly-distributed. If every voter had an equal say in the election, then the fact that the majority of the electorate live in urban areas would mean that urban interests would outweigh rural ones, and the country would get governed largely in the interests of the big cities.

The electoral college system, AIUI, is designed to prevent that. It means that a candidate cannot win simply by getting all the support from the big cities; he (or she) would need broad support across the whole country, in urban and rural areas. Both interests would be represented in the government.

In essence, it changes the system from counting votes purely by the number of people, to counting them by land area as well. Geographic as well as demographic voting.

At least, that's the theory. I've no idea how well this works out in practice. But a lot of the posts here seem just as uninformed as I am. To argue intelligently about the electoral college system, you need first to understand its aims! Then we can discuss whether it's implemented well, whether geographical counting is a good idea, whether it shifts the balance far enough (or too far) towards that