Creation of paid libraries for .NET, Android, etc. - Is it profitable?

Question

.NET

As soon as the Internet appeared, there are many such sites.
The site contains a library, one or more, solving certain problems. For example, working with office documents (PDF, DOC, DOCX, XLS, XLSX, PPT, all sorts of reports) without MS Office. Or controls for the GUI.
There are also such "sharks" as DevExpress and Telerik, there are not libraries, but entire frameworks. There is even Embarcadero (former CodeGear, former Borland), its Delphi - in fact, there is a large framework + compiler + IDE.
But what about these? All of them (and even small ones) usually have a long history, 5 years, or even 15-20.
What if you do this in 2017?
What exactly will be done. Of course, this will not be a framework, but first one library with a narrow specialization, say, for the same PDF, XLS / XLSX, reports or DOC.
Still, for example, there is the idea of ​​a protocol based on TCP and the corresponding either on the client and on the server. It will be a very thin layer that will retain the flexibility of TCP and will not rest on a specific task (like HTTP, which rested on the concept of "question and answer"), but at the same time will ensure the rapid creation of fairly reliable client-servers as simple ("question -response"), and complex, where the server listens to each client as long as it is available, and the client listens to the server. At one time I was looking for analogues, but I didn’t find libraries that were worthwhile. This is usually written individually in each company. And why write if there is a ready-made one that is flexible enough - that is, my system?
Really good work will be done in the chosen narrow direction. Although the idea itself is not new for a long time (especially PDF / XLS / XLSX / DOC), and it’s hard to come up with unique features here, but in general (speed, API convenience, quality of implementation of the formats themselves, quality of documentation, examples, speed of development (RAD) , cross-platform, cost finally) the library will greatly outperform any of its counterparts.
So what kind of income can be expected in the near future - months, the first couple of years?
What clients should you focus on - software companies, non-software companies, or maybe you can make money on freelancers (they need to be very cheap, but they don’t think long)?
How to unwind? (Habr - of course, but somehow it's weak)
I foresee the answers "you are behind the times, now open source rules."
But I don't see any benefit from it.
It is good as a portfolio - to study during the student period, so that later you can add links to your resume.
And a serious project, on which several people are working, somehow does not want to give it away for free, hoping only for donations. Have you donated a lot yourself? :) There are five of us, and not one - not even once.

Answer 1

The request "pdf dll for .net buy" has a huge output of commercial libraries. How will yours be the best of all this huge list? Now there is high competition in IT, a huge number of programming languages ​​that replace each other.
That's it. There is a project, it was written. They got money from him. Some of its parts decided to monetize in order to earn more.
I have not heard about your system. And why should I buy your system if I have a staff of highly qualified programmers who write expensive software. What you were looking for because you were too lazy / didn’t know / didn’t understand / didn’t want to understand, then others take and write. If you come up with something that is not on the market, then yes.
Software companies have a huge staff of programmers, they can write themselves. Freelancer sense? He has an hourly pay, it is more profitable for him to write it himself, and if he is a freelancer with experience, then he already has a huge amount of ready-made code that travels from project to project, he will not really need your library if it does not have something unique.
None, you haven't written or sold anything yet. You have not even decided what you will write and to whom you will sell.
Your budget for promotion will be higher than your earnings. On one hub you will not take off.
You're not right.
This is just your vision.
There is also paid technical support. As an example, look at how much a paid nginx support costs, there the amount is from $2500. And only a few people started writing it. You are confusing concepts, OpenSource is NOT free software, it is open source software.
It's you, the main support for open source comes from the investments of the big companies that this software uses. For example, the creator of WhatsApp donated $1,000,000
And most importantly. If you want to sell something, you need programming skills least of all.

Answer 2

.NET is now massively losing popularity, like all "paid" technologies in general. Times are different now, libraries "for money" are of little interest to anyone.

Answer 3

But I don't see any benefit from it.
It is good as a portfolio - to study during the student period, so that later you can add links to your resume.
And a serious project, on which several people are working, somehow does not want to be distributed for free,
Here, RedHat managers would probably be upset if they read this ...
But CentOS, however, is distributed free of charge . And the basic version of the VmWare hypervisor is free (the key must be generated on their website, yes - that's all). And the basic version of Zimbra. And the basic version of this...and that... You
can sell the program once . You can always sell support. Why do you think there has been such an unequivocal transition from the perpetual licensing model to the "subscription" model? For a year, for two, for a month? Because the big offices, who used to bet on support with a parting, realized that they had lost. I bought AutoCAD - and have been using it for ten years. Yes, it is old, not fashionable, not feature-packed. But he solves the problem, and I do not need more. But now I have to "buy" it every year - or switch to another package. Pavel
told you wonderfully - to sell something, the least you need is the ability to program. You need a business plan - a tedious, dull, completely non-IT process of calculating who a potential consumer is, how much he is, how much he can pay, how to license and whether it is necessary ...