If you're looking to build a list of influencers to evangelise your product / service, here's the match in heaven: BuzzSumo + BuzzStream. These 2 SaaS are totally unrelated despite their common "Buzz" term. But they work perfectly together.
The best way to use BuzzSumo + BuzzStream to find and message the right influencers is to start with a search on BuzzSumo, right here (after signing up): https://app.buzzsumo.com/amplification/twitter-influencers
Try for instance to search for "community manager" among bloggers who are active influencers. You'll get 29 pages of results.
Then, page per page, you use the magic "create a prospecting list" feature of BuzzStream (as you can see I also have Evernote and Pinterest in my Chrome add-ons). Simply right click on the page to use this tool.
It will instantly generate a list of websites you'll be able to browse to curate a list of influencers (just remove the first and last websites if needed, it's usually Sumo and Moz).
Very often BuzzStream will find a contact email address but sometimes you'll need some extra help, using the highly efficient Emailhunter extension (the little fox icon turns orange when it finds emails on the page).
Add contacts to a BuzzStream project and launch your outreach campaigns. Then start the outreach. You can personalise each message on the fly before sending the email. Thanks to BuzzSumo + BuzzStream (+ Hunter), you'll get mentions, features and even potentially some business offers.