.NET Invoice

Rob Walling was a consultant making good money on hourly rates, but he was trapped in the trading-time-for-money treadmill. After years of reading finance books and side projects that generated minimal revenue (FeedShot at $100/month, forum software that didn't gain traction), he realized he needed to find or build something with recurring revenue. The catalyst came when he visited a client using a hosted time tracker that charged users $10/month—the client had only seven employees but was bringing in substantial annual recurring revenue with money appearing in the bank account automatically each month. This sparked an obsession: could he acquire or build something similar?

Rob began trolling acquisition sites like SitePoint and eBay for existing products, looking for something already generating revenue that he could scale. By pure coincidence, he found .NET Invoice—a clean, well-coded ASP.NET invoicing application that ranked highly for relevant keywords and was generating $700-$1,000/month organically with no paid advertising. The two developers who built it were looking for someone with marketing skills to help them sell better. After seeing the source code and demos, Rob made an offer of $10,000; they countered at $15,000. He eventually acquired it for $11,000—nearly all the money in his business bank account. It was a terrifying bet, but he couldn't give up.

The product already had customers, but Rob quickly discovered the revenue numbers were inflated through artificial email launches. The actual baseline was closer to $200/month, and the codebase had serious issues—literally math errors in an invoicing product. Customers were furious. Rob worked nights and weekends over six weeks, fixing dozens of bugs while maintaining his full-time consulting job. He did all support via Gmail himself, personally responding to angry customers and promising to fix everything. Instead of hiding behind the "unsupported version" excuse, he committed to supporting everyone.

Rob made a bold pricing experiment: he raised the price from $98 to $295. The next month, the product sold three copies at the higher price point, generating $900—nearly their rent payment. This taught him a critical lesson: the market could bear higher prices. Over time, he built the product to peak revenues of around $5,000/month, with most months between $2,000-$4,000. The real wins came from SEO and organic keyword rankings, which required continuous optimization. He built a toolkit in copywriting, customer support, and online marketing. However, the market had a ceiling. The product appealed primarily to .NET developers—either consultants who wanted to white-label it or developers who preferred to own their own data rather than use SaaS. The niche was real but small.

As Rob's other ventures (HitTail, Drip, his book, and MicroConf) grew exponentially, .NET Invoice became a distraction. After a few years of being a side project, he brought on a business partner (coincidentally, a mutual friend of the person he'd originally emailed about partnering) and eventually handed the product to him entirely. The partnership worked out well, and they remain on good terms. While .NET Invoice never became the $20-30k/month product Rob once dreamed of, it was invaluable as a stair-step—his first product to generate real recurring revenue, his first deep dive into SEO and marketing, and his first lesson in pricing power. Looking back, the $11,000 investment was terrifying but transformative, teaching him that having his back to the wall forced him to ship, iterate, and persist.