There is a growing movement in the realm of internet businesses. It is described with different names but one common keyword among those is "indie". This movement is comprised of small companies, usually by solo or duo founders, who tackle a problem that other businesses have without taking external funding (i.e. VC money). This is why they are called indie.
Apart from being bootstrapped, they have some other common attributes:
Not all of them have all those attributes, but there is a pattern.
Basecamp is one of the pioneers of this model of building internet businesses and DHH, the CTO of Basecamp, is a vocal adherent. Another well-known inaugural community of the movement is that of the Startups for the rest of us podcast.
KnowHub also considers itself part of this movement.
Other "indie" businesses are Ghost, Baremetrics, NomadList, Apex. IndieHackers is a community for this movement and they maintain a very interesting list with hundreds of companies that are part of the trend.
Sure, there may be something like this, but why is it interesting?
This indie trend is identifiable as separate because it positions itself opposite to the Silicon Valley way of doing internet businesses. The SV playbook dictates that every company should strive to build the future and become a billion dollar company. To do that, every company has to grow exponentially, and if it can achieve that, it doesn't need to make money. It can use money from funding. In order to get funded, company founders exchange stock for money. This means that the founders relinquish pieces of the company's future profits in order to maximize those profits for everyone.
There are some significant benefits  to being a unicorn. Primarily, you get to do things that will have massive impact on a global scale. Furthermore, the evolution of a unicorn is a large public corporation. At that point you have unlimited resources, which means there is ample room for experimentation. These experiments, if successful, can lead to leaps in innovation (and subsequently revenue). And if the experiments don't have the desirable outcome, you can discontinue them and lose virtually nothing. This is impossible for a new company, as the company itself is "the experiment".
Indie companies aspire to sustainable growth and start with little to no initial capital. This is part of the reason why indie businesses charge more than you would expect. For example, Simple Analytics launched recently and there were some negative reactions on HN regarding the price point of $14. This product does significantly less and costs much more than Google Analytics, so why choose it?
There are several answers. Some of them are:
All in all, indie internet businesses is a growing movement and it's interesting to see in what ways it will evolve. KnowHub is part of this trend and we hope it grows as there are no downsides to it.
 Peter Thiel, in his book Zero to One talks in detail about them.