Iowa and New Hampshire

I never understood why the Iowa caucases and the New Hampshire Primaries are such as big deal. I know they are the first ones, and often candidates that do well there build momentum and gain more media attention. However, both state are very small. They have no large cities. They aren't very racially/ethnically diverse. The population of Iowa is about 3 million, the population of New Hampshire is about 1.3 million. If you consider that the US has 300 million people so only a little over 1% of the population is in these states. So much attention for such as small portion of the country. So to me (and I'm sure lots of other people too) all the media attention on these 2 states is way overrated.