I'm glad you're respecting robots.txt, but please say what your bot's user agent string is, so site administrators can block specifically your bot.
I'm loathe to be so negative on a "Show HN" post, but I strongly believe that this business is disreputable and that businesses of this type cause harm to the Internet. There may be value in finding blogs/bloggers matching specific queries; perhaps take email addresses out of the equation?
[1] http://www.spamhaus.org/consumer/definition/
Edited to add: just yesterday I received an email from someone I don't know asking me to try out his "weather API." The same email was clearly sent to a lot of different people, and it was sent to an address I have posted on websites, so it must have been scraped. I suspect the sender didn't think his email was spam, since he didn't try to hide his identity or use a bot net to send it. But being unsolicited and bulk, it was spam. It was sent via Mandrill so I reported it to Mandrill's abuse team; most people would probably just mark it as spam, harming the reputation of Mandrill's mail servers, thus making it more difficult for Mandrill to be used for legitimate email sending. I have a feeling "blogger outreach" would follow a similar pattern as this.