How to Build a $750/Month WordPress Business: An Interview with Founder, Jack Slingerland

Hello! My name is Jack Slingerland and I’m the founder of! Kernl is a WordPress plugin and theme update service. It also handles WordPress license management, WordPress analytics, and WordPress git deployment.

Key Statistics

  • Monthly Revenue: $750 and growing steadily
  • Date Started / Years in Business: The first commit in Kernl’s codebase was December 14, 2014 but we didn’t open for alpha testing until March 2015 or so.
  • Location / Homebase: Kernl is located in Raleigh, NC.
  • Number of Employees: Just me!

In the beginning (or even now) do you maintain a full time job while launching?

Trying to hold down a full-time job and launch a product can be tough and requires some serious time management skills. I currently work full time as a Lead Senior Software Engineer at an education technology company and then try to spend 1 hour a night working on Kernl, and 2 hours in the early morning on weekends. It doesn’t always work out that way but trying to be consistent is helpful for pushing things over the finish line.

The other thing I’d like to say about having a full-time job and successfully launching a product is that you need to know EXACTLY what you will be doing before you sit down to work. It could be banging out a blog post, setting up some scheduled tweets, writing code, or customer support.

Whatever it is, just make sure you are ready to work when you sit down. I accomplish this by keeping a Trello board with all of my work in it and doing monthly “sprints”. At the beginning of the month, I take 30 minutes and organize my upcoming work and set goals for the month. Its very similar to Agile except over a longer time span because of the limited amount of time I can spend working on Kernl.

I try and stay flexible and realistic with my goals that way I don’t feel down if I don’t accomplish everything I had set out to do. You have to celebrate the small wins to stay motivated.

How did you acquire customers/subscribers/users?

Getting your first customers requires some creative thinking if you’re bootstrapped like Kernl is. For Kernl there were a few channels that I pursued when I was just starting out.

Twitter – When Kernl launched there was only 1 or 2 competitors out there and they often did a terrible job of keeping their customers happy. I initially reached out to every single one of these upset people and told them about Kernl, why we were better, and why they should give us a shot. In general, this tactic worked very well and I still have quite of a few of those first customers today.

StackOverflow – At its core Kernl is a developer tool and developers always go to StackOverflow for help. I was able to answer a few questions on StackOverflow that are a continued source of referrals and new users. This doesn’t always work (sometimes answers get flagged), but for the most part, I’ve been happy with the results.

Reddit – There are a lot of niche sub-reddit’s about software development and several of them are dedicated to WordPress development. Being able to answer questions in those communities was a decent source of traffic.

Paid Advertising – I’ve never had any luck with this. I’ve probably spent over $1000 on paid ads but never converted a single user. At this point, I think my ads are the issue, not paid to advertise 😉

Content Marketing – This has easily been the best source for sign-ups. Generate a useful article and shop it around the WordPress community. If it’s good enough, it picks up steam, drives traffic, and some of that traffic converts to sign-ups. I’ve lately been experimenting with paid guest posts on some higher traffic WordPress content sites as well. The jury is still out on the effectiveness of that though.

What software / platforms / tools have you utilized since launch?

Over the course of Kernl’s (short) lifetime I’ve used a bunch of great tools to help get things off the ground.

MEAN Stack – At the time I started Kernl I already knew Angular, Node, had some experience with Express, and almost none with Mongo. I decided to use Mongo just to learn it better. If I had known Kernl was going to take off the way that it id I wouldn’t have used Mongo though. Not because Mongo is bad but because Kernl’s data is highly relational so something like PostgreSQL or MySQL would have been a better choice.

Digital Ocean – I can’t speak highly enough about Digital Ocean. I’ve grown from a single $5 droplet to the highly available setup that I have today without much trouble and all while still keeping the monthly bills down. If you’re just getting started and don’t want to invest much in infrastructure, Digital Ocean is a great place to get started.

AWS S3 – All of Kernl’s uploaded files and builds are stored on S3. Ideally, I would like Kernl’s files hosted in one of Digital Ocean’s data centres, but their storage offering is quite mature enough for me yet. – Kernl’s Mongo database is hosted through It’s a highly available setup that I never have to think about, has great visualizations, and an easy web interface to make edits on the fly (which is great for support)!. Easily the best $18 I spend every month.

SendGrid – While Kernl doesn’t send a lot of emails, when we do send them having a reliable provider is crucial. SendGrid has been great over the past 2 years.

Stripe – Billing would be a huge pain in the a** if not for Stripe and it keeps getting better! I know that their pricing can seem expensive, but honestly, if you need to worry about 2.9% you are very likely already successful.

How did you fund your startup and how do you make money/revenue?

Kernl is 100% bootstrapped. As far as making money goes, Kernl is a SaaS business with several different plans and some add-on features. Our base plan costs $8/month and our most expensive is $60/month.

To date, what have been your biggest challenges as a company? What have you done to overcome them?

Marketing and sales! I’m an engineer originally so figuring out the best way to marketing and sell a product has been a huge learning experience. Even after a few years I think there are a lot of things that I could be doing better, for instance…

  • Sponsor WordCamps
  • More sponsored content slots on popular blogs
  • More relevant Tweets and Facebook posts
  • More focus on getting Kern’s Google page rank score up.

If you had to do it all over again, would you? What would you do differently?

Yes, absolutely! It’s been a wonderful experience interacting and learning from the wider WordPress community and learning how to build a product from the ground up. Aside from that, it has also been great for my personal brand. Being able to put “successfully bootstrapped a SaaS web app to profitability” on your resume has a tendency to open doors.

I don’t know if I would change much if I had to do it over. Overall I made fairly good choices from the beginning that have served me well so far.

Lastly, if anyone reading this wants to know more about your company… where do we send them?

You can always head over to our website to learn more about Kernl. If you want to learn more about me you can follow me on Twitter at @jackslingerland.