I want to spread the music I make with my band. As we are playing a style of music that has its own niche in the music scene (black metal / screamo), it is hard to spread the music to people that might find it interesting.

As we already have our music on bandcamp, spotify, iTunes, last.fm and other platforms, are there ways of getting exposure in the USA (we are from Europe) and reach as many people as possible? (this is not for any financial gain, just to spread the music).

For more information on our band, it is called "Terzij de Horde", our music can be placed in the same genre as Deafheaven, so called post black metal.

You can listen to our music on our terzijdehorde.bandcamp.com

Looks like you hit most of the good places. My recommendation would be to start hitting up blogs or communities. Warning about communities/forums - it's best to have been there a while and to know the etiquette and atmosphere around such things.

One blog I'm often looking to for music is toxicbreedsfunhouse.blogspot.com - might be worth getting a post in there if you can.

Listening to the stuff and liking it thus far. Keep on keepin' on - sometimes it takes a lot of hoofwork to get this stuff. Got a blog/facebook page where you'll announce tour dates/post up links/videos/pictures?

Yes, we are on facebook (because that is the main platform now for social interaction with people that might like your music). facebook.com

I will take a look at toxicbreedsfunhouse.blogspot.com, thank you for the tip, much appreciated.

The thing about communities/forums is that the etiquette is very important on there. A lot of people that are sort of in-crowd and you don't want to spam your band for the sake of it (that annoys me on facebook where bands post updates multiple times a day with useless announcements, so we try to walk the fine line).