Launching a software as a service business is as hard as any other business. However, since the initial investment is much lower, you're taking fewer risks by trying to build web or mobile apps that people may want to use.
Here are the steps to start a software business that has a bigger chance of being successful.
Build an Minimal Viable Product
The first step is to just build a prototype that prospects can use to get feedback and then to improve the app. Also, we need it to see if people actually need your software as a service.
Just build this as quickly as possible. If it's successful, then you can clean it up, write tests, etc.
Without this, everything else is probably a waste of time. Because the feedback will let you gauge the market and see if they need your app to solve their problems.
Build an Online Presence
Most people that'll be using your software are probably going to be someone on the Internet. This is why it's important to get feedback from them. To find these people, you have to have your own online presence. Your online presence is going to be on social media like Facebook, Twitter, this site, your own blog, or other niche sites.
This is the most crucial step. This is just as important as building the prototype. You need to show your prototype to people you built online to other people online.
You may also want to sell ads to get more traffic to your social media presence.
Have a Free Beta
A free beta will attract more people to try your stuff to see if it's useful. It also eliminates the need to collect payment by integrating your app with payment providers from the start. This means the minimal viable product is shipped faster.
Set up a Feedback Mechanism
Again, this is where your social media and online presence comes in handy. You can collect feedback from social media to improve your product. Just have one place to collect all your feedback, act on them, and then get more people to try out your prototype.
Email Marketing
Email marketing is useful because you can send them surveys and other information about your app. You shouldn't do too much selling. Just set up links to your email subscribe form everywhere and also display an email list subscribe form on your blog. The best way is to add a popup to do that. Even though it may be annoying to some, it works.
Conclusion
The most important step to creating your own software as a service is to do marketing and getting feedback. Coding isn't very important since you don't even know if people want your product yet. Therefore, the first step is to communicate rather than doing engineering.