An 'any software you want' approach to marketing?

I want to start a software business. It's probably been said a million times before on this forum, and software start-up's being in such abundance is one of the reasons for this question.

I don't know what software to spend my time building. I have a few ideas, but I'm not entirely convinced there's a market for them, and none have really excited me. As I've said, as everybody and his brother can offer their different software ideas - it's very difficult to target a niche that nobody else has. So my idea is to market (probably via flyers to begin with) bespoke software development for all small to medium-sized businesses, no matter what the software. This is a way of not only obviously getting customers, but gathering info about what people will part with their money for. I'm omitting a lot of details here for the sake of this OP - for example on the flyers I could list the kind of ideas I have and get people thinking about what they may need software in their business for.

Can anyone provide any feedback on this approach?
Has anybody any recommendations for such a novice to owning their own software business?

This is feasible and often known as doing consultant work. Some people use consultant work as a revenue stream to sustain their business while they are building a scalable product.

If you would like to go down this path, I suggest creating a portfolio site to showcase your skills and start to market your services in your local area. Start searching/attending meetups and events where you think your potential customers will hang around. From my experience, the need to create custom Web applications is rather common so you can start building your portfolio from there.

If you do this enough and depending on the opportunities you meet, you may be able to find yourself doing the same type of Web applications for many clients, then you can generalize and produce an SaaS for the many people with similar needs out there.

Depending on your location, you may be able to start as a freelancer at bidding sites like ODesk, vWorker, ScriptLance, etc. In general the price people pay there can hardly sustain living in a developed country, though.

Following TimJ's angle, you should be a bit more creative than just flyers.

Here's an idea to improve upon (or ignore, your choice). Flavor to suit:

1) Target a few business types that you believe would be capable of paying for development + meet your intellectual curiosity. Make sure they are local businesses - otherwise, you could face an uphill battle getting approval.

2) Find the decision makers. Ask for feedback on an idea - No stings attached x hours of development time on a pressing business issue they have. Make it a realistic number, and stipulate that it has to be specific to their business process - no creating a twitter account / simple website, etc. Gauge interest. Pitch it as a contest - whomever gives the best suggestion will win.

3) IF good feedback, create a specific page talking about the conditions. Set a launch date, & make sure that you follow up with the initial contacts. Also send it to all competitors in the area.

4) Promote it. Pitch the local newspapers about a story were you are helping local companies compete in a down economy. Pitch online press sources. Status updates on twitter.

5) Award it, get more press, do the work. If work is successful, get testimonials. Contact newspaper for followup story.

Now you have established yourself with the community, and hopefully had an successful experience. Now you can start charging - consider the first project a marketing expense.