37signals can build simple — almost trivial — software and earn three million customers because they absolutely will not compromise on their philosophy of simplicity, transparency, and owning their own company, and that’s something millions of people respect and support. Competitors could build trivial web applications too (as Joel Spolsky is fond of saying, “Their software is just a bunch of text fields!”), but without the single-minded obsession it’s just software with no features.
To remain un-copyable, your One Thing needs to be not just central to your existence, but also difficult to achieve. Google’s algorithm, combined with the hardware and software to implement a search of trillions of websites in 0.2 seconds, is hard to replicate; it took hundreds (thousands?) of really smart people at Microsoft and Yahoo years to catch up. 37signals’ ranting platform — a blog with 131k followers and a best-selling book — is nearly impossible to build even with a full-time army of insightful writers.
