I have got some good links from fashion bloggers for my retail site using twitter.
I just added loads of fashion/beauty bloggers and then replied to tweets, started conversations and built up some friendly relationships
Obviously people are much more likely to do you a favour if you are on a friendly basis, much more than if your a stranger in a cold email anyway.
Apart from normal stuff like buying advertising space, a couple of bloggers have given me links in the last couple of weeks for making them new banners (I'm not bad on photoshop and I quite enjoy being creative)
I also did another special favour for a pretty popular blogger that I'm not going to go into (not like that ;P) but I've got a very good free advertisement space for next month out of it that would of been pretty expensive otherwise.
So I guess you just have to find people, be friendly, start conversations and try and find an angle where you can do them a favour/or simply get them interested and on your site in the first place if your content is that good.