Does not matter what field it is, If it is unique.

I've been studying this for some time and found some quite extraordinary things. Some programmers have made $100,000s out of writing the right program. Marketing is not an issue for them, it's quite easy to sell it.

On a similar topic. I have come up with a method of locking a 'software container' (like Adobe's PDF reader but something else that would have to be custom written) to a PC so that the document CANNOT under ANY circumstance be copied to another PC and be opened. The method is quite simple but it needs to be carefully programmed to prevent hacking.

What this means to eBook publishers is that their documents can be copied with impunity but can never be read away from the target computer.

More light on the software marketing and selling will be highly appreciated.

It might be better idea to investigate what the people need and what they are ready to pay for, instead of inventing unique software that may be no one will be willing to buy. May be, think about what you can sell, what customer group you can easy target and it could help in defining the software specification.

You don't have to be unique. The 'next big thing' is not around the corner. The obvious has happened in the software writing market and that is, it has fragmented into specializations. All the main things are being done and have been done for years. It is only the speed and power of PCs that is taking sofware forward and giving commercial advantage to programmers who are first with the fastest, latest iterations of software.

Take a look at Solidworks, it's everything a prototyping engineer could want, but it's $10,000 per licence. Defeating or even competing with Solidworks would take $5 or $6 million. Whereas writing niche market software is extremely lucrative for the programming and support hours that it costs and can be done by a lone programmer.

Also, there are many 'engines' that a programmer can purchase and put his own shell to it. There's lots of 'dead' software out there too where the author has placed it in the public domain, sometimes with source code and if you purchase that, modify it to your own purpose you can sell that if it's changed in a sufficiently dramatic way. There's also lots of free source code out there that can help with programming whatever you want.

Some programmers are stuck with having to give away every version until they think they have got something good and then start selling it at version 6 for $25. That's an ok way to go but not the best way if you want a faster return on your programming effort.