Do you have any examples or references of "story" that I can learn from?
PS: Yes, I know about exclusives. Therefore, I didn't do a mass-mail. I mailed one, waited, mailed another, waited. But still no reply.
Maybe by changing your subject line to fit their typical "story" type. Like using LifeHacker as an example: "How my software improves conversions by 35% - overnight." - just something a tad bit sensational.
Also, you might want to consider doing "favors" for the bloggers, like giving them a free account & personal assistance in setting up some a/b tests for things like their events or contests, etc.
Also, you can try to reach them more personally (but they usually don't like that) - if you have a particular persons email, give that a try or twitter if they're following you, dm them or even a call, if you have skype credit. I believe Jason Kincaid from techcrunch is jkincaid here on HN, that's a starting point.
Lastly, you might want to approach blogs with smaller audiences, that are targeted, like smashingmagazine.com or appvita.com - something that 90% tech people read.
Good luck, I hope this was helpful.
You have plenty of data to play with and I'm sure there are extremely interesting points you can make.