My advice is make it OpenSource and let it gain momentum. It'll be very difficult to compete in this saturated market, unless you go open-source which will encourage everyone to test your software, give feedback and increase market-penetration. Afterwards, once your software is fully established in the market (and got more advanced), you will become a consultant. You will also be able to give support and modify the software or make modules for it on demand. The size of the market is not as important as market penetration.