Honestly, I am not much of a fan of any of these bands. But. They have done everything right. There is a reason they do well, and get signed.
They spend a ton of time obviously writing music that appeals to a broad audience of what is popular right now, they record quality records (i.e. spend the money on it and do it right), they play shows with some thought as to what the show will accomplish, they promote adequately, and they TOUR. Even if just regionally, they tour.
Basically. They work hard. Like them or not, this entire group of bands from the Twin Cities probably works harder than 99% of the bands that bitch about them. And say what you want about myspace... It is an invaluable tool with music right now. A fully integrated social network that bands can use to reach audiences GLOBALLY. Hate to say it, but it is one of the KEY things the labels look at these days.
They have an advantage though, most of them. They are young, they don't have to work 40+ hrs. a week alot of the time, and they probably find a way to get funding for the band so they can do this. Its basic business 101. Get funding, create a product (band/album), market and brand product (myspace/web promotions), promote product in a calculated manner to maximize exposure (myspace/touring). Pretty simple concept. And they are doing it.
It has nothing to do with the genre. It has more to do with the business practices these bands are following. Ill give them this. They're smart, and they run good business.