Betalist (which others mentioned) seems to deliver at least 300ish signups for a generally useful service. Unfortunately my latest project is targeting only Her

Betalist (which others mentioned) seems to deliver at least 300ish signups for a generally useful service. Unfortunately my latest project is targeting only Heroku users who need to install SSL [1] so I needed to do something else. The best thing I found was actually Twitter. I setup a search column in Tweetdeck that would pop an alert on my desktop if anyone tweeted "Heroku" and "SSL" in the same tweet. I'd then just @message them and ask if they'd want to try the alpha (Heroku has strict phases with increasing numbers of users you need to onboard before they'll release the add-on to General Availability). If someone agreed to be an early tester, I'd try to "upsell" them into taking the time to do a Skype onboarding call with me where I'd just watch them in real time try and add a SSL cert to their app. This was likely the fastest and most productive thing I've ever done to rapidly improve the product, hugely benefical. 1 - https://addons.heroku.com/expeditedssl https://addons.heroku.com/expeditedssl