Get 10,000 people who SAID they want your product.
People are sharing tweets that you know means they need your product. You can download a list of all the people who shared those tweets from BuzzSumo, upload to an email finder and get emails.
To see a subject header mentioning a specific tweet of yours is as personal as it gets. Depending on how many people sent the tweet, you can download up to 10,000 per month. Most often you'll get a figure of around 3,000 to 5,000 shares. This will result in anywhere from 20 to 500 email addresses. The number depends on whether it's a b2b type tweet as Anymail finder needs a name and domain in order to look for an email. A domain such as xyz.tumblr.com will not work, so avoid private individuals, business accounts are more likely to mention a viable domain.