How Damon Chen Acquired and Grew PDF.ai

In May 2023, Damon Chen acquired a PDF chat service that one developer had built over a weekend. The product had no payment feature, but Chen relaunched it as PDF.ai and reported monthly revenue above $60,000 by that November. He had already grown Testimonial.to, a customer testimonial collection service, into a paid business. For his second business, he drew on that experience to choose a product, decide how to sell it, and hire someone to develop it.

Code and customers from his first business

Chen worked as a software engineer at Cisco for eight years. At the company he worked with the Linux kernel, operating systems, and C and C++, and while building personal web services he learned frontend and backend development. When remote work began in 2020, he put the two hours a day he had spent commuting into personal projects. He built five apps that year.

Among them, IndieLog was a community where developers shared their work process and daily life in short videos. Chen wanted to create a space where developers working alone could get to know each other, and he interacted with users directly. When he later built Testimonial, he reused about 80% of IndieLog's code. He moved the video feature that had been used for developer communication to a purpose where businesses secure customer testimonials.

Testimonial's core function was connecting the collection and publishing of testimonials. When a business sent a customer the address of a dedicated collection page, the customer could leave their experience as text or video. The business chose from the collected testimonials and embedded them on its website, showing the experience of existing customers to visitors considering a purchase. The value of this service was that there was no need to build a collection page and publishing feature yourself.

In May 2021, the monthly recurring revenue of Testimonial that Chen disclosed was $2,258, and there were 81 active subscribers. Subscription income that had not existed four months earlier was now coming in. He recalled that around this time he began learning marketing, sales, and customer support. At a company there was no chance to talk with customers directly, but in his own business he listened to customer requests every day and reflected them in the product.

How his first product expanded his options

Testimonial's promotion was tied to the process of customers making their testimonials public. When the Testimonial logo appeared on a review collection page called 'Wall of Love', other business owners who saw it signed up for the service. The feature to remove the logo was also used as a reason to convert to paid. The result a customer needed became a channel for meeting new customers.

In a November 2022 interview, Testimonial's annual recurring revenue was reported as $400,000. When he reached that scale, Chen hired his first employee to help with marketing. By the time he was reviewing a new product, he had customers paying repeatedly, sales experience, and a foundation for dividing up work. The starting conditions for expanding into several businesses were different from when he built his first project.

The problem that led to PDF.ai also came from conversations with Testimonial customers. Some ecommerce businesses struggled to collect good reviews, and Chen took note of cases where buyers left negative reviews because they had not properly understood how to use the product. He looked into a chatbot that would let people ask questions of product manuals provided as PDFs and get answers. Having worked on collecting testimonials, he ended up examining the customer experience that comes before a testimonial is created.

Buying a weekend project to confirm paid demand

The product Chen acquired was originally named Looseleaf.ai, and the developer was Josh. The early version could handle only one PDF in a conversation at a time, and it had no monetization feature. It drew attention on social media and then was put up for sale, and Chen decided to acquire it after seeing that response. Interest was confirmed, but whether there were customers willing to pay to use it still had to be tested.

The acquisition price was about $20,000, and the PDF.ai domain cost another $10,000. Chen gained a working product and a name that made its purpose easy to recognize. By paying those costs up front, he shortened the time needed for initial development. What happened next depended on adding payments and finding buyers.

The product offered at relaunch was a $99 lifetime deal. The first customer appeared within 24 hours of starting sales, and more than 300 people bought over three months. This confirmed that attention received on social media led to actual payments. Based on this sales result, Chen put more resources into PDF.ai.

Payments from lifetime-deal sales were used to hire a full-time developer. By securing someone to take over development with money received from early customers, he could reduce the burden of handling work on both products alone as the founder. However, this money is one-time income, so he also had to build a subscription business to cover service operating costs and customer support that continue afterward. This is where the way of selling that secures early cash and the revenue structure that can be maintained in the long term need to be viewed separately.

Different customer acquisition channels for each product

The name PDF.ai suggested the file format and the function provided. Chen explained that the main inflow source at the time was Google organic search, and that people searching for 'PDF AI' found the service. Because the expression users searched for was close to the product name, it was also easy to understand the purpose of a service discovered in search. The name and domain were used as a means of introducing and making the product memorable.

Outside of search, he used short videos and introductions on external sites. According to a case analysis published in October 2023, PDF.ai had staff who continuously posted content on Instagram and ran video promotion. The process of uploading a file, asking a question, and getting an answer was easy to show even in a short demonstration. While Testimonial became known through testimonials published on customer websites, PDF.ai met customers through search demand and content that showed usage situations.

In a November 2023 interview with Peter Yang, the annual recurring revenue Chen disclosed was more than $800,000 for Testimonial and more than $500,000 for PDF.ai. Together the two products exceeded $1.3 million. This is a figure that converts the recurring subscription revenue at the time into an annual scale, and it is distinct from net profit after deducting labor and operating costs. The change in this period was that, on top of the business he grew first, he also secured substantial recurring revenue from the product he acquired.

Testimonial kept growing while he ran the new product. Chen later announced that Testimonial's annual recurring revenue had reached $1 million. The growth of the second business did not proceed in a form that immediately replaced the first, and the two products together formed a portfolio.

Changing how he operated as the number of products grew

In this process, the work Chen was responsible for also changed. In addition to building features himself, he had to decide which product to spend development money on and which tasks to hand to others. In the PDF.ai interview, he also introduced a service for managing the pay of overseas employees and contractors as an operating tool. As a business he started alone grew, it changed into a form where work for each product was divided among several people.

Work to widen the scope of the existing product also continued. In the September 2026 Testimonial feature guide, collecting and publishing testimonials was joined by brand mention monitoring, customer case study collection, recommendation intent surveys, and follow-up email automation. These features are connected within the work of understanding customer experience and using it in marketing. While adding separate products, he is also expanding the work that a product which already has customers can take on.

At the same time, Chen's public portfolio lists, besides Testimonial and PDF.ai, PDFgen, which creates PDFs with artificial intelligence, and Docsium, which uses ChatGPT in Google Docs, Sheets, and Slides. The scope of the products widened from reading documents to creating documents and using them inside work tools. Each product has a separate name, but there are adjacent areas among the work they handle.

What stands out in Chen's business development is that the resources available when starting the next product kept changing. Early on he reused code he had already written, later he acquired a product that already existed, and after confirming paid demand he hired development staff. Behind his ability to own several products was the choice to use the technology, sales experience, and cash secured in earlier attempts in a way that fit the next stage.