This is a cool project. I'm mostly a designer, but am familiar with PhantomJS.
I don't see a blog on your site. Have you considered writing about the technology? I'd think search would be a great growth mechanism for something like this. Certainly there are a ton of people searching for questions related to Phantom. I'd look around Stack Overflow and possibly Quora for topic ideas and then write posts answering those questions.
Yes, "inbound marketing" (a blog) is probably the biggest accelerator to growth I can (and should) do. I'm holding off for now though, as I need to make the product more friendly to business users first. Right now PhantomJsCloud is focused on developers, so I need to make some non-dev friendly tooling first. That's my excuse at least.
Regarding StackOverflow, yes, that's actually how I validated the free MVP (answering SO questions and if my product might be beneficial, providing a link to my product) but generally those traffic sources don't seem to scale very well past MVP validation. I haven't tried Quora though, I will add that to my todo list :)
I don't want to second guess your strategy—but here I go. If your tool is appealing to developers _and_ you have identified a way to reach developers, then I think you should seriously consider focusing on that.
Consider for a moment Dropbox: For a very long time they and their competitors catered to the needs of designers and other freelancers who had to share large files with clients. Was Dropbox anathema to IT departments? Yes, totally. But building a product that appeals to corporate IT departments has been a huge undertaking.
If your goal is to build a successful business, the easiest way to do that may be reaching critical mass with developers and then maybe finding ways to offer more value to your exiting (developer) customers and charging accordingly.
As I love self-deprecation, I also love it when people second-guess me :) Thanks for the feedback, yes you are right actually. I want to provide better tooling so that it requires less development effort (and make it easier for less sophisticated devs to use) but I am wrong to lump in "business users" as you are absolutely right that it would be a distraction to entertain that demographic.
Just to provide a single data point, I run JavaScript Weekly and Node Weekly (which have 140K subscribers altogether) and if you had the right content that would interest my readers, even if ultimately it promotes your service, I'd link to it :-)
I don't see a blog on your site. Have you considered writing about the technology? I'd think search would be a great growth mechanism for something like this. Certainly there are a ton of people searching for questions related to Phantom. I'd look around Stack Overflow and possibly Quora for topic ideas and then write posts answering those questions.