Twitter. If you are solving a real pain point, there will likely be people complaining about it on twitter. Search for those phrases and offer to solve their problem. I got my first couple hundred users this way. Then it grew organically from there.
I'm aware that I owe you an email reply OP, sorry I have been busy and have stopped cold emailing customers.<p>Right now, I'm selling to retail / real estate (<a href="http://www.retailwizard.co.uk" rel="nofollow">http://www.retailwizard.co.uk</a> / <a href="http://www.propertywizard.io" rel="nofollow">http://www.propertywizard.io</a>) so to get customers I literally go to their workplace & ask them for 5 minutes of their time. I did try emailing as you know, but I have found going to speak to to them face-to-face to be more effective for my niche.<p>Obviously email works for other sectors, something I'm looking to explore again in the future.
Thanks for asking a very relevant question.<p>Another tip I can share is going to meetups of your target customer and building relationships.<p>We're building something that's fairly overlapping (i.e. landing pages, etc. ) but we're more focused on the marketing automation piece. Good luck!