How A Personal Need Sparked A 5 Figure In-App Feedback Business

Revenue: $4,500/mo
October 16, 2018


Give a summary of Doorbell. What does it do? When was it launched? How much monthly revenue is it currently generating?

My name is Philip Manavopoulos and I built Doorbell.

Doorbell is a solution to gather in-app feedback from your customers, and manage those conversations.

Doorbell launched in the summer of 2013, and was a side project for almost 5 years. In April 2018, I managed to start working on it full time.

Doorbell’s monthly revenue is currently just over $4,500.

How did you get the idea for Doorbell? Did you do anything to validate the idea before building the product?

I started working on Doorbell 2 reasons:

  • I wanted to find a simple, lightweight, and affordable solution to be able to easily get feedback from an Android app I had built
  • I was itching to start a new side-project

In terms of launching I technically did it all wrong, and didn’t really follow any of the advice that everyone typically gives. No research, no customer interviews, I just started “scratching my own itch”, building the tool I wish I had found.

Sure I could have used a different tool that was close enough to what I needed, but I assumed that I probably wouldn’t be the only one who needed this. So despite no plan to have a big launch, no customer acquisition plan, no marketing plan, and zero validation, I started coding away.

Talk about the MVP for Doorbell. What features did it have? How did you decide what to include and what to leave out? How long did it take to build it?

The first part of Doorbell I worked on was the Android SDK, and a basic web interface where I could see the feedback coming in, and reply to those messages.

Because I didn’t really have any launch plans, I kept working on Doorbell until I had a web SDK, and both Android and iOS working. If I was planning a launch I probably would have not waited until they were all available.

The first version though only took about 2 months, and had features that were still well out of any MVP scope (allowing customers to have a custom domain). I completely left out everything relating to billing, and there was no way to pay for it.

Talk about the tech stack for the MVP. Any advice?

I wanted to build the product relatively quickly, while also learning something new along the way. So I decided to use PHP as a language that I was familiar with, but try out a new framework in Laravel (version 4 was just released in May 2013, just before I started). For the front-end I stuck purely with the basic tech stack I was familiar with, and I’ve kept it to this day (no fancy Single-Page Application framework, good old fashioned HTML generated by the backend).

So the main piece of advice I’d give is don’t get sucked into using new shiny technologies which will delay you, stick with what you know!

What were the total expenses for the MVP?

The total expenses of the MVP were the domain name (about $30, and $5 for a DigitalOcean server). And obviously my time, which wasn’t too many hours since I had a full time job at the same time!

Talk about the founding team. How many founders? Who are they? Who was responsible for what?

Doorbell was (and still is) a 1 person team. I’ve worked on all parts of the application, outsourcing some little bits along the way when I needed help. The main bits I needed some help with was the first version of the iOS SDK, and designing the logo (I had the idea for the logo, but 0 Photoshop knowledge)

Talk about the MVP launch. What exactly did you do? How did it go?

The MVP launch was unplanned and underwhelming. Since I was mostly planning on working on a side project instead of launching a business, there wasn’t much of a launch. I wrote a blog post, but had no audience. So there was essentially no grand launch when the MVP was completed.

I posted Doorbell to some websites such as, and submitted it to Google.

The next closest thing to a launch, and the first major event to bring in visitors and paying customers was being posted on ProductHunt. Although that was unplanned, and it was a surprise to me when it was posted.

ProductHunt was the place where the first paying customers came from.

Since launch, how are you getting users for Doorbell?

The majority of Doorbell’s users have come organically, either from Google or from word of mouth recommendations.

The free plan of Doorbell has been great to get people testing it in smaller side-projects, and then if there’s a need for a similar tool in their main job, they sometimes recommend Doorbell.

Quora has also been a very good source of growth, by answering questions and helping curate answer wikis for questions regarding feedback tool recommendations.

How has the product evolved since launch? What features have you added? What features do you plan to add?

The product has evolved over time by listening to my customers. As more and more people use it, I collect feedback (through Doorbell, of course) to see what people want out of the product.

That has driven most of the features that have been built, and most that are still planned.

Letting your customers tell you what they want (or what’s missing) is far better than any competitor analysis you can do!

How has the team changed since launch?

No growth for the team, still just a 1 person team!

How has the tech stack changed since launch?

No change in the tech stack, it has remained identical. And it has comfortably scaled to thousands of customers and millions of feedback messages captured.

How have the expenses changed since launch?

The expenses have increased over time, in a couple of ways. The main ones being server costs (needing slightly bigger servers, as demand increases), so my Digital Ocean bill has grown (up to $80/month now).

The other main way is my Postmark bill, since more messages are sent (email notifications) (up to $100/month now).

And finally, the last main way that expenses have increased is me taking a salary, now that I work full time on it.

Other than those there are smaller expenses that have been introduced over time, but they have all been on a relatively small scale (less than $200/month total).

What’s your business model? How is revenue growing over time?

The business model is SaaS subscription revenue. For the first 2 years of Doorbell’s existence it wasn’t even covering the operating expenses. But in the last 3 years the revenue has increased to ~$4,500.

doorbell revenue

Give a description of what you do, on a day-to-day basis, to run Doorbell.

Since the beginning I’ve had a big focus on support. So that’s something that is constant in my effort, always try and resolve customer issues as soon as physically possible. It’s a great way to take advantage of being a super small team, where I can resolve an issue within minutes, rather than a large team where communication is harder and it could potentially be months for the issue to be solved.

What are the things that most helped you build Doorbell into a successful business?

Discovering Pieter Levels on Twitter when he was doing his 12 startups in 12 months.

Finding out that there is a whole community of people out there trying to create micro-businesses really inspired me to try and grow Doorbell to a sustainable MRR where I could have to freedom to work just on Doorbell, or other projects like it.

What were your biggest challenges to date? How did you overcome them?

The biggest challenge to date has been learning to deal with burnout. And it is a recurring/repeating challenge.

Especially while working full time and building Doorbell, there were sometimes long stretches of time when I had to keep myself away and take a break.

It’s really important to be able to identify it early on and take that time off. Or cut down to just doing the absolute minimum (which is probably some basic support).

If that extra feature is delayed by another week or two, that won’t make or break your business. But if you burn yourself out into needing a 6 month break, that can definitely kill it!

Knowing what you know now, what would you change about Doorbell’s journey to date?

Charge from day 1, and don’t undercharge for it. I’ve had a few iterations of pricing on Doorbell, and every time I’ve changed the pricing it’s had a substantial impact on revenue growth.

How has your life changed because of XYZ? Has it improved? Or gotten worse? Overall, are you happier?

Overall my life has changed my being able to have more flexibility in my life. I now have the ability to travel while working (with more freedom than a remote job would allow), and I get to choose how much and when I work.

There are some difficulties with being a solo founder, so finding a shared workspace to work from is pretty necessary to avoid isolation. But it’s still worth taking the plunge and working on it full time!

Overall, I’m definitely happier!

How can one learn more about Doorbell?

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